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993 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Linus Torvalds
|
feb889fb40 |
mm: don't put pinned pages into the swap cache
So technically there is nothing wrong with adding a pinned page to the
swap cache, but the pinning obviously means that the page can't actually
be free'd right now anyway, so it's a bit pointless.
However, the real problem is not with it being a bit pointless: the real
issue is that after we've added it to the swap cache, we'll try to unmap
the page. That will succeed, because the code in mm/rmap.c doesn't know
or care about pinned pages.
Even the unmapping isn't fatal per se, since the page will stay around
in memory due to the pinning, and we do hold the connection to it using
the swap cache. But when we then touch it next and take a page fault,
the logic in do_swap_page() will map it back into the process as a
possibly read-only page, and we'll then break the page association on
the next COW fault.
Honestly, this issue could have been fixed in any of those other places:
(a) we could refuse to unmap a pinned page (which makes conceptual
sense), or (b) we could make sure to re-map a pinned page writably in
do_swap_page(), or (c) we could just make do_wp_page() not COW the
pinned page (which was what we historically did before that "mm:
do_wp_page() simplification" commit).
But while all of them are equally valid models for breaking this chain,
not putting pinned pages into the swap cache in the first place is the
simplest one by far.
It's also the safest one: the reason why do_wp_page() was changed in the
first place was that getting the "can I re-use this page" wrong is so
fraught with errors. If you do it wrong, you end up with an incorrectly
shared page.
As a result, using "page_maybe_dma_pinned()" in either do_wp_page() or
do_swap_page() would be a serious bug since it is only a (very good)
heuristic. Re-using the page requires a hard black-and-white rule with
no room for ambiguity.
In contrast, saying "this page is very likely dma pinned, so let's not
add it to the swap cache and try to unmap it" is an obviously safe thing
to do, and if the heuristic might very rarely be a false positive, no
harm is done.
Fixes:
|
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Hugh Dickins
|
15b4473617 |
mm/lru: revise the comments of lru_lock
Since we changed the pgdat->lru_lock to lruvec->lru_lock, it's time to fix the incorrect comments in code. Also fixed some zone->lru_lock comment error from ancient time. etc. I struggled to understand the comment above move_pages_to_lru() (surely it never calls page_referenced()), and eventually realized that most of it had got separated from shrink_active_list(): move that comment back. Link: https://lkml.kernel.org/r/1604566549-62481-20-git-send-email-alex.shi@linux.alibaba.com Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Tejun Heo <tj@kernel.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Jann Horn <jannh@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Alexander Duyck <alexander.duyck@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Chen, Rong A" <rong.a.chen@intel.com> Cc: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mika Penttilä <mika.penttila@nextfour.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Alexander Duyck
|
2a5e4e340b |
mm/lru: introduce relock_page_lruvec()
Add relock_page_lruvec() to replace repeated same code, no functional change. When testing for relock we can avoid the need for RCU locking if we simply compare the page pgdat and memcg pointers versus those that the lruvec is holding. By doing this we can avoid the extra pointer walks and accesses of the memory cgroup. In addition we can avoid the checks entirely if lruvec is currently NULL. [alex.shi@linux.alibaba.com: use page_memcg()] Link: https://lkml.kernel.org/r/66d8e79d-7ec6-bfbc-1c82-bf32db3ae5b7@linux.alibaba.com Link: https://lkml.kernel.org/r/1604566549-62481-19-git-send-email-alex.shi@linux.alibaba.com Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com> Acked-by: Hugh Dickins <hughd@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Tejun Heo <tj@kernel.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Chen, Rong A" <rong.a.chen@intel.com> Cc: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Jann Horn <jannh@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mika Penttilä <mika.penttila@nextfour.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Alex Shi
|
6168d0da2b |
mm/lru: replace pgdat lru_lock with lruvec lock
This patch moves per node lru_lock into lruvec, thus bring a lru_lock for each of memcg per node. So on a large machine, each of memcg don't have to suffer from per node pgdat->lru_lock competition. They could go fast with their self lru_lock. After move memcg charge before lru inserting, page isolation could serialize page's memcg, then per memcg lruvec lock is stable and could replace per node lru lock. In isolate_migratepages_block(), compact_unlock_should_abort and lock_page_lruvec_irqsave are open coded to work with compact_control. Also add a debug func in locking which may give some clues if there are sth out of hands. Daniel Jordan's testing show 62% improvement on modified readtwice case on his 2P * 10 core * 2 HT broadwell box. https://lore.kernel.org/lkml/20200915165807.kpp7uhiw7l3loofu@ca-dmjordan1.us.oracle.com/ Hugh Dickins helped on the patch polish, thanks! [alex.shi@linux.alibaba.com: fix comment typo] Link: https://lkml.kernel.org/r/5b085715-292a-4b43-50b3-d73dc90d1de5@linux.alibaba.com [alex.shi@linux.alibaba.com: use page_memcg()] Link: https://lkml.kernel.org/r/5a4c2b72-7ee8-2478-fc0e-85eb83aafec4@linux.alibaba.com Link: https://lkml.kernel.org/r/1604566549-62481-18-git-send-email-alex.shi@linux.alibaba.com Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com> Acked-by: Hugh Dickins <hughd@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Rong Chen <rong.a.chen@intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Alexander Duyck <alexander.duyck@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Jann Horn <jannh@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Mika Penttilä <mika.penttila@nextfour.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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|
Alex Shi
|
9df4131439 |
mm/compaction: do page isolation first in compaction
Currently, compaction would get the lru_lock and then do page isolation
which works fine with pgdat->lru_lock, since any page isoltion would
compete for the lru_lock. If we want to change to memcg lru_lock, we have
to isolate the page before getting lru_lock, thus isoltion would block
page's memcg change which relay on page isoltion too. Then we could
safely use per memcg lru_lock later.
The new page isolation use previous introduced TestClearPageLRU() + pgdat
lru locking which will be changed to memcg lru lock later.
Hugh Dickins <hughd@google.com> fixed following bugs in this patch's early
version:
Fix lots of crashes under compaction load: isolate_migratepages_block()
must clean up appropriately when rejecting a page, setting PageLRU again
if it had been cleared; and a put_page() after get_page_unless_zero()
cannot safely be done while holding locked_lruvec - it may turn out to be
the final put_page(), which will take an lruvec lock when PageLRU.
And move __isolate_lru_page_prepare back after get_page_unless_zero to
make trylock_page() safe: trylock_page() is not safe to use at this time:
its setting PG_locked can race with the page being freed or allocated
("Bad page"), and can also erase flags being set by one of those "sole
owners" of a freshly allocated page who use non-atomic __SetPageFlag().
Link: https://lkml.kernel.org/r/1604566549-62481-16-git-send-email-alex.shi@linux.alibaba.com
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Alex Shi
|
d25b5bd8a8 |
mm/lru: introduce TestClearPageLRU()
Currently lru_lock still guards both lru list and page's lru bit, that's ok. but if we want to use specific lruvec lock on the page, we need to pin down the page's lruvec/memcg during locking. Just taking lruvec lock first may be undermined by the page's memcg charge/migration. To fix this problem, we will clear the lru bit out of locking and use it as pin down action to block the page isolation in memcg changing. So now a standard steps of page isolation is following: 1, get_page(); #pin the page avoid to be free 2, TestClearPageLRU(); #block other isolation like memcg change 3, spin_lock on lru_lock; #serialize lru list access 4, delete page from lru list; This patch start with the first part: TestClearPageLRU, which combines PageLRU check and ClearPageLRU into a macro func TestClearPageLRU. This function will be used as page isolation precondition to prevent other isolations some where else. Then there are may !PageLRU page on lru list, need to remove BUG() checking accordingly. There 2 rules for lru bit now: 1, the lru bit still indicate if a page on lru list, just in some temporary moment(isolating), the page may have no lru bit when it's on lru list. but the page still must be on lru list when the lru bit set. 2, have to remove lru bit before delete it from lru list. As Andrew Morton mentioned this change would dirty cacheline for a page which isn't on the LRU. But the loss would be acceptable in Rong Chen <rong.a.chen@intel.com> report: https://lore.kernel.org/lkml/20200304090301.GB5972@shao2-debian/ Link: https://lkml.kernel.org/r/1604566549-62481-15-git-send-email-alex.shi@linux.alibaba.com Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com> Acked-by: Hugh Dickins <hughd@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Alexander Duyck <alexander.duyck@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Jann Horn <jannh@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Mika Penttilä <mika.penttila@nextfour.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Alex Shi
|
afca9157fd |
mm/vmscan: remove lruvec reget in move_pages_to_lru
Isolated page shouldn't be recharged by memcg since the memcg migration isn't possible at the time. All pages were isolated from the same lruvec (and isolation inhibits memcg migration). So remove unnecessary regetting. Thanks to Alexander Duyck for pointing this out. Link: https://lkml.kernel.org/r/1604566549-62481-12-git-send-email-alex.shi@linux.alibaba.com Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com> Acked-by: Hugh Dickins <hughd@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Michal Hocko <mhocko@kernel.org> Cc: Alexander Duyck <alexander.duyck@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: "Chen, Rong A" <rong.a.chen@intel.com> Cc: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Jann Horn <jannh@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Mika Penttilä <mika.penttila@nextfour.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Alex Shi
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75cc3c9161 |
mm/lru: move lock into lru_note_cost
We have to move lru_lock into lru_note_cost, since it cycle up on memcg tree, for future per lruvec lru_lock replace. It's a bit ugly and may cost a bit more locking, but benefit from multiple memcg locking could cover the lost. Link: https://lkml.kernel.org/r/1604566549-62481-11-git-send-email-alex.shi@linux.alibaba.com Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com> Acked-by: Hugh Dickins <hughd@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Alexander Duyck <alexander.duyck@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: "Chen, Rong A" <rong.a.chen@intel.com> Cc: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Jann Horn <jannh@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mika Penttilä <mika.penttila@nextfour.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Alex Shi
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3d06afab52 |
mm/vmscan: remove unnecessary lruvec adding
We don't have to add a freeable page into lru and then remove from it. This change saves a couple of actions and makes the moving more clear. The SetPageLRU needs to be kept before put_page_testzero for list integrity, otherwise: #0 move_pages_to_lru #1 release_pages if !put_page_testzero if (put_page_testzero()) !PageLRU //skip lru_lock SetPageLRU() list_add(&page->lru,) list_add(&page->lru,) [akpm@linux-foundation.org: coding style fixes] Link: https://lkml.kernel.org/r/1604566549-62481-6-git-send-email-alex.shi@linux.alibaba.com Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com> Acked-by: Hugh Dickins <hughd@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Tejun Heo <tj@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Alexander Duyck <alexander.duyck@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: "Chen, Rong A" <rong.a.chen@intel.com> Cc: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Jann Horn <jannh@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mika Penttilä <mika.penttila@nextfour.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Gustavo A. R. Silva
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01359eb201 |
mm: fix fall-through warnings for Clang
In preparation to enable -Wimplicit-fallthrough for Clang, fix a couple of warnings by explicitly adding a break statement instead of just letting the code fall through to the next, and by adding a fallthrough pseudo-keyword in places where the code is intended to fall through. Link: https://github.com/KSPP/linux/issues/115 Link: https://lkml.kernel.org/r/f5756988b8842a3f10008fbc5b0a654f828920a9.1605896059.git.gustavoars@kernel.org Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Yang Shi
|
d12b8951ad |
mm: truncate_complete_page() does not exist any more
Patch series "mm: misc migrate cleanup and improvement", v3.
This patch (of 5):
The commit
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logic.yu
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8d87d07c92 |
mm/vmscan.c: remove the filename in the top of file comment
No point in having the filename inside the file. Link: https://lkml.kernel.org/r/20201115141541.3878-1-hymmsx.yu@gmail.com Signed-off-by: logic.yu <hymmsx.yu@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Lukas Bulwahn
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2b47a24cee |
mm/vmscan: drop unneeded assignment in kswapd()
The refactoring to kswapd() in commit
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Shakeel Butt
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013339df11 |
mm/rmap: always do TTU_IGNORE_ACCESS
Since commit |
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Nicholas Piggin
|
2da9f6305f |
mm/vmscan: fix NR_ISOLATED_FILE corruption on 64-bit
Previously the negated unsigned long would be cast back to signed long which would have the correct negative value. After commit |
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Yu Zhao
|
ed0173733d |
mm: use self-explanatory macros rather than "2"
Signed-off-by: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alex Shi <alex.shi@linux.alibaba.com> Link: http://lkml.kernel.org/r/20200831175042.3527153-2-yuzhao@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
Matthew Wilcox (Oracle)
|
3efe62e466 |
mm/vmscan: allow arbitrary sized pages to be paged out
Remove the assumption that a compound page has HPAGE_PMD_NR pins from the page cache. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: SeongJae Park <sjpark@amazon.de> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: "Huang, Ying" <ying.huang@intel.com> Link: https://lkml.kernel.org/r/20200908195539.25896-12-willy@infradead.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
Hui Su
|
01c4776ba0 |
mm/vmscan: fix comments for isolate_lru_page()
fix comments for isolate_lru_page(): s/fundamentnal/fundamental Signed-off-by: Hui Su <sh_def@163.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/20200927173923.GA8058@rlk Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
Chunxin Zang
|
069c411de4 |
mm/vmscan: fix infinite loop in drop_slab_node
We have observed that drop_caches can take a considerable amount of
time (<put data here>). Especially when there are many memcgs involved
because they are adding an additional overhead.
It is quite unfortunate that the operation cannot be interrupted by a
signal currently. Add a check for fatal signals into the main loop so
that userspace can control early bailout.
There are two reasons:
1. We have too many memcgs, even though one object freed in one memcg,
the sum of object is bigger than 10.
2. We spend a lot of time in traverse memcg once. So, the memcg who
traversed at the first have been freed many objects. Traverse memcg
next time, the freed count bigger than 10 again.
We can get the following info through 'ps':
root:~# ps -aux | grep drop
root 357956 ... R Aug25 21119854:55 echo 3 > /proc/sys/vm/drop_caches
root 1771385 ... R Aug16 21146421:17 echo 3 > /proc/sys/vm/drop_caches
root 1986319 ... R 18:56 117:27 echo 3 > /proc/sys/vm/drop_caches
root 2002148 ... R Aug24 5720:39 echo 3 > /proc/sys/vm/drop_caches
root 2564666 ... R 18:59 113:58 echo 3 > /proc/sys/vm/drop_caches
root 2639347 ... R Sep03 2383:39 echo 3 > /proc/sys/vm/drop_caches
root 3904747 ... R 03:35 993:31 echo 3 > /proc/sys/vm/drop_caches
root 4016780 ... R Aug21 7882:18 echo 3 > /proc/sys/vm/drop_caches
Use bpftrace follow 'freed' value in drop_slab_node:
root:~# bpftrace -e 'kprobe:drop_slab_node+70 {@ret=hist(reg("bp")); }'
Attaching 1 probe...
^B^C
@ret:
[64, 128) 1 | |
[128, 256) 28 | |
[256, 512) 107 |@ |
[512, 1K) 298 |@@@ |
[1K, 2K) 613 |@@@@@@@ |
[2K, 4K) 4435 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@|
[4K, 8K) 442 |@@@@@ |
[8K, 16K) 299 |@@@ |
[16K, 32K) 100 |@ |
[32K, 64K) 139 |@ |
[64K, 128K) 56 | |
[128K, 256K) 26 | |
[256K, 512K) 2 | |
In the while loop, we can check whether the TASK_KILLABLE signal is set,
if so, we should break the loop.
Signed-off-by: Chunxin Zang <zangchunxin@bytedance.com>
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Chris Down <chris@chrisdown.name>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Link: https://lkml.kernel.org/r/20200909152047.27905-1-zangchunxin@bytedance.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
Hugh Dickins
|
8d8869ca5d |
mm: fix check_move_unevictable_pages() on THP
check_move_unevictable_pages() is used in making unevictable shmem pages
evictable: by shmem_unlock_mapping(), drm_gem_check_release_pagevec() and
i915/gem check_release_pagevec(). Those may pass down subpages of a huge
page, when /sys/kernel/mm/transparent_hugepage/shmem_enabled is "force".
That does not crash or warn at present, but the accounting of vmstats
unevictable_pgs_scanned and unevictable_pgs_rescued is inconsistent:
scanned being incremented on each subpage, rescued only on the head (since
tails already appear evictable once the head has been updated).
5.8 commit
|
||
Xunlei Pang
|
e3336cab25 |
mm: memcg: fix memcg reclaim soft lockup
We've met softlockup with "CONFIG_PREEMPT_NONE=y", when the target memcg doesn't have any reclaimable memory. It can be easily reproduced as below: watchdog: BUG: soft lockup - CPU#0 stuck for 111s![memcg_test:2204] CPU: 0 PID: 2204 Comm: memcg_test Not tainted 5.9.0-rc2+ #12 Call Trace: shrink_lruvec+0x49f/0x640 shrink_node+0x2a6/0x6f0 do_try_to_free_pages+0xe9/0x3e0 try_to_free_mem_cgroup_pages+0xef/0x1f0 try_charge+0x2c1/0x750 mem_cgroup_charge+0xd7/0x240 __add_to_page_cache_locked+0x2fd/0x370 add_to_page_cache_lru+0x4a/0xc0 pagecache_get_page+0x10b/0x2f0 filemap_fault+0x661/0xad0 ext4_filemap_fault+0x2c/0x40 __do_fault+0x4d/0xf9 handle_mm_fault+0x1080/0x1790 It only happens on our 1-vcpu instances, because there's no chance for oom reaper to run to reclaim the to-be-killed process. Add a cond_resched() at the upper shrink_node_memcgs() to solve this issue, this will mean that we will get a scheduling point for each memcg in the reclaimed hierarchy without any dependency on the reclaimable memory in that memcg thus making it more predictable. Suggested-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Xunlei Pang <xlpang@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Chris Down <chris@chrisdown.name> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Link: http://lkml.kernel.org/r/1598495549-67324-1-git-send-email-xlpang@linux.alibaba.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Matthew Wilcox (Oracle)
|
6c357848b4 |
mm: replace hpage_nr_pages with thp_nr_pages
The thp prefix is more frequently used than hpage and we should be consistent between the various functions. [akpm@linux-foundation.org: fix mm/migrate.c] Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: David Hildenbrand <david@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Link: http://lkml.kernel.org/r/20200629151959.15779-6-willy@infradead.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
Randy Dunlap
|
1eba09c15d |
mm/vmscan.c: delete or fix duplicated words
Drop the repeated word "marked". Change "time time" to "same time". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Zi Yan <ziy@nvidia.com> Link: http://lkml.kernel.org/r/20200801173822.14973-14-rdunlap@infradead.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
Joonsoo Kim
|
4002570c5c |
mm/vmscan: restore active/inactive ratio for anonymous LRU
Now that workingset detection is implemented for anonymous LRU, we don't need large inactive list to allow detecting frequently accessed pages before they are reclaimed, anymore. This effectively reverts the temporary measure put in by commit "mm/vmscan: make active/inactive ratio as 1:1 for anon lru". Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Link: http://lkml.kernel.org/r/1595490560-15117-7-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Joonsoo Kim
|
aae466b005 |
mm/swap: implement workingset detection for anonymous LRU
This patch implements workingset detection for anonymous LRU. All the infrastructure is implemented by the previous patches so this patch just activates the workingset detection by installing/retrieving the shadow entry and adding refault calculation. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Link: http://lkml.kernel.org/r/1595490560-15117-6-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Joonsoo Kim
|
3852f6768e |
mm/swapcache: support to handle the shadow entries
Workingset detection for anonymous page will be implemented in the following patch and it requires to store the shadow entries into the swapcache. This patch implements an infrastructure to store the shadow entry in the swapcache. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Link: http://lkml.kernel.org/r/1595490560-15117-5-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Joonsoo Kim
|
170b04b7ae |
mm/workingset: prepare the workingset detection infrastructure for anon LRU
To prepare the workingset detection for anon LRU, this patch splits workingset event counters for refault, activate and restore into anon and file variants, as well as the refaults counter in struct lruvec. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Link: http://lkml.kernel.org/r/1595490560-15117-4-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Joonsoo Kim
|
b518154e59 |
mm/vmscan: protect the workingset on anonymous LRU
In current implementation, newly created or swap-in anonymous page is started on active list. Growing active list results in rebalancing active/inactive list so old pages on active list are demoted to inactive list. Hence, the page on active list isn't protected at all. Following is an example of this situation. Assume that 50 hot pages on active list. Numbers denote the number of pages on active/inactive list (active | inactive). 1. 50 hot pages on active list 50(h) | 0 2. workload: 50 newly created (used-once) pages 50(uo) | 50(h) 3. workload: another 50 newly created (used-once) pages 50(uo) | 50(uo), swap-out 50(h) This patch tries to fix this issue. Like as file LRU, newly created or swap-in anonymous pages will be inserted to the inactive list. They are promoted to active list if enough reference happens. This simple modification changes the above example as following. 1. 50 hot pages on active list 50(h) | 0 2. workload: 50 newly created (used-once) pages 50(h) | 50(uo) 3. workload: another 50 newly created (used-once) pages 50(h) | 50(uo), swap-out 50(uo) As you can see, hot pages on active list would be protected. Note that, this implementation has a drawback that the page cannot be promoted and will be swapped-out if re-access interval is greater than the size of inactive list but less than the size of total(active+inactive). To solve this potential issue, following patch will apply workingset detection similar to the one that's already applied to file LRU. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Link: http://lkml.kernel.org/r/1595490560-15117-3-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Joonsoo Kim
|
ccc5dc6734 |
mm/vmscan: make active/inactive ratio as 1:1 for anon lru
Patch series "workingset protection/detection on the anonymous LRU list", v7.
* PROBLEM
In current implementation, newly created or swap-in anonymous page is
started on the active list. Growing the active list results in
rebalancing active/inactive list so old pages on the active list are
demoted to the inactive list. Hence, hot page on the active list isn't
protected at all.
Following is an example of this situation.
Assume that 50 hot pages on active list and system can contain total 100
pages. Numbers denote the number of pages on active/inactive list (active
| inactive). (h) stands for hot pages and (uo) stands for used-once
pages.
1. 50 hot pages on active list
50(h) | 0
2. workload: 50 newly created (used-once) pages
50(uo) | 50(h)
3. workload: another 50 newly created (used-once) pages
50(uo) | 50(uo), swap-out 50(h)
As we can see, hot pages are swapped-out and it would cause swap-in later.
* SOLUTION
Since this is what we want to avoid, this patchset implements workingset
protection. Like as the file LRU list, newly created or swap-in anonymous
page is started on the inactive list. Also, like as the file LRU list, if
enough reference happens, the page will be promoted. This simple
modification changes the above example as following.
1. 50 hot pages on active list
50(h) | 0
2. workload: 50 newly created (used-once) pages
50(h) | 50(uo)
3. workload: another 50 newly created (used-once) pages
50(h) | 50(uo), swap-out 50(uo)
hot pages remains in the active list. :)
* EXPERIMENT
I tested this scenario on my test bed and confirmed that this problem
happens on current implementation. I also checked that it is fixed by
this patchset.
* SUBJECT
workingset detection
* PROBLEM
Later part of the patchset implements the workingset detection for the
anonymous LRU list. There is a corner case that workingset protection
could cause thrashing. If we can avoid thrashing by workingset detection,
we can get the better performance.
Following is an example of thrashing due to the workingset protection.
1. 50 hot pages on active list
50(h) | 0
2. workload: 50 newly created (will be hot) pages
50(h) | 50(wh)
3. workload: another 50 newly created (used-once) pages
50(h) | 50(uo), swap-out 50(wh)
4. workload: 50 (will be hot) pages
50(h) | 50(wh), swap-in 50(wh)
5. workload: another 50 newly created (used-once) pages
50(h) | 50(uo), swap-out 50(wh)
6. repeat 4, 5
Without workingset detection, this kind of workload cannot be promoted and
thrashing happens forever.
* SOLUTION
Therefore, this patchset implements workingset detection. All the
infrastructure for workingset detecion is already implemented, so there is
not much work to do. First, extend workingset detection code to deal with
the anonymous LRU list. Then, make swap cache handles the exceptional
value for the shadow entry. Lastly, install/retrieve the shadow value
into/from the swap cache and check the refault distance.
* EXPERIMENT
I made a test program to imitates above scenario and confirmed that
problem exists. Then, I checked that this patchset fixes it.
My test setup is a virtual machine with 8 cpus and 6100MB memory. But,
the amount of the memory that the test program can use is about 280 MB.
This is because the system uses large ram-backed swap and large ramdisk to
capture the trace.
Test scenario is like as below.
1. allocate cold memory (512MB)
2. allocate hot-1 memory (96MB)
3. activate hot-1 memory (96MB)
4. allocate another hot-2 memory (96MB)
5. access cold memory (128MB)
6. access hot-2 memory (96MB)
7. repeat 5, 6
Since hot-1 memory (96MB) is on the active list, the inactive list can
contains roughly 190MB pages. hot-2 memory's re-access interval (96+128
MB) is more 190MB, so it cannot be promoted without workingset detection
and swap-in/out happens repeatedly. With this patchset, workingset
detection works and promotion happens. Therefore, swap-in/out occurs
less.
Here is the result. (average of 5 runs)
type swap-in swap-out
base 863240 989945
patch 681565 809273
As we can see, patched kernel do less swap-in/out.
* OVERALL TEST (ebizzy using modified random function)
ebizzy is the test program that main thread allocates lots of memory and
child threads access them randomly during the given times. Swap-in will
happen if allocated memory is larger than the system memory.
The random function that represents the zipf distribution is used to make
hot/cold memory. Hot/cold ratio is controlled by the parameter. If the
parameter is high, hot memory is accessed much larger than cold one. If
the parameter is low, the number of access on each memory would be
similar. I uses various parameters in order to show the effect of
patchset on various hot/cold ratio workload.
My test setup is a virtual machine with 8 cpus, 1024 MB memory and 5120 MB
ram swap.
Result format is as following.
param: 1-1024-0.1
- 1 (number of thread)
- 1024 (allocated memory size, MB)
- 0.1 (zipf distribution alpha,
0.1 works like as roughly uniform random,
1.3 works like as small portion of memory is hot and the others are cold)
pswpin: smaller is better
std: standard deviation
improvement: negative is better
* single thread
param pswpin std improvement
base 1-1024.0-0.1 14101983.40 79441.19
prot 1-1024.0-0.1 14065875.80 136413.01 ( -0.26 )
detect 1-1024.0-0.1 13910435.60 100804.82 ( -1.36 )
base 1-1024.0-0.7 7998368.80 43469.32
prot 1-1024.0-0.7 7622245.80 88318.74 ( -4.70 )
detect 1-1024.0-0.7 7618515.20 59742.07 ( -4.75 )
base 1-1024.0-1.3 1017400.80 38756.30
prot 1-1024.0-1.3 940464.60 29310.69 ( -7.56 )
detect 1-1024.0-1.3 945511.40 24579.52 ( -7.07 )
base 1-1280.0-0.1 22895541.40 50016.08
prot 1-1280.0-0.1 22860305.40 51952.37 ( -0.15 )
detect 1-1280.0-0.1 22705565.20 93380.35 ( -0.83 )
base 1-1280.0-0.7 13717645.60 46250.65
prot 1-1280.0-0.7 12935355.80 64754.43 ( -5.70 )
detect 1-1280.0-0.7 13040232.00 63304.00 ( -4.94 )
base 1-1280.0-1.3 1654251.40 4159.68
prot 1-1280.0-1.3 1522680.60 33673.50 ( -7.95 )
detect 1-1280.0-1.3 1599207.00 70327.89 ( -3.33 )
base 1-1536.0-0.1 31621775.40 31156.28
prot 1-1536.0-0.1 31540355.20 62241.36 ( -0.26 )
detect 1-1536.0-0.1 31420056.00 123831.27 ( -0.64 )
base 1-1536.0-0.7 19620760.60 60937.60
prot 1-1536.0-0.7 18337839.60 56102.58 ( -6.54 )
detect 1-1536.0-0.7 18599128.00 75289.48 ( -5.21 )
base 1-1536.0-1.3 2378142.40 20994.43
prot 1-1536.0-1.3 2166260.60 48455.46 ( -8.91 )
detect 1-1536.0-1.3 2183762.20 16883.24 ( -8.17 )
base 1-1792.0-0.1 40259714.80 90750.70
prot 1-1792.0-0.1 40053917.20 64509.47 ( -0.51 )
detect 1-1792.0-0.1 39949736.40 104989.64 ( -0.77 )
base 1-1792.0-0.7 25704884.40 69429.68
prot 1-1792.0-0.7 23937389.00 79945.60 ( -6.88 )
detect 1-1792.0-0.7 24271902.00 35044.30 ( -5.57 )
base 1-1792.0-1.3 3129497.00 32731.86
prot 1-1792.0-1.3 2796994.40 19017.26 ( -10.62 )
detect 1-1792.0-1.3 2886840.40 33938.82 ( -7.75 )
base 1-2048.0-0.1 48746924.40 50863.88
prot 1-2048.0-0.1 48631954.40 24537.30 ( -0.24 )
detect 1-2048.0-0.1 48509419.80 27085.34 ( -0.49 )
base 1-2048.0-0.7 32046424.40 78624.22
prot 1-2048.0-0.7 29764182.20 86002.26 ( -7.12 )
detect 1-2048.0-0.7 30250315.80 101282.14 ( -5.60 )
base 1-2048.0-1.3 3916723.60 24048.55
prot 1-2048.0-1.3 3490781.60 33292.61 ( -10.87 )
detect 1-2048.0-1.3 3585002.20 44942.04 ( -8.47 )
* multi thread
param pswpin std improvement
base 8-1024.0-0.1 16219822.60 329474.01
prot 8-1024.0-0.1 15959494.00 654597.45 ( -1.61 )
detect 8-1024.0-0.1 15773790.80 502275.25 ( -2.75 )
base 8-1024.0-0.7 9174107.80 537619.33
prot 8-1024.0-0.7 8571915.00 385230.08 ( -6.56 )
detect 8-1024.0-0.7 8489484.20 364683.00 ( -7.46 )
base 8-1024.0-1.3 1108495.60 83555.98
prot 8-1024.0-1.3 1038906.20 63465.20 ( -6.28 )
detect 8-1024.0-1.3 941817.80 32648.80 ( -15.04 )
base 8-1280.0-0.1 25776114.20 450480.45
prot 8-1280.0-0.1 25430847.00 465627.07 ( -1.34 )
detect 8-1280.0-0.1 25282555.00 465666.55 ( -1.91 )
base 8-1280.0-0.7 15218968.00 702007.69
prot 8-1280.0-0.7 13957947.80 492643.86 ( -8.29 )
detect 8-1280.0-0.7 14158331.20 238656.02 ( -6.97 )
base 8-1280.0-1.3 1792482.80 30512.90
prot 8-1280.0-1.3 1577686.40 34002.62 ( -11.98 )
detect 8-1280.0-1.3 1556133.00 22944.79 ( -13.19 )
base 8-1536.0-0.1 33923761.40 575455.85
prot 8-1536.0-0.1 32715766.20 300633.51 ( -3.56 )
detect 8-1536.0-0.1 33158477.40 117764.51 ( -2.26 )
base 8-1536.0-0.7 20628907.80 303851.34
prot 8-1536.0-0.7 19329511.20 341719.31 ( -6.30 )
detect 8-1536.0-0.7 20013934.00 385358.66 ( -2.98 )
base 8-1536.0-1.3 2588106.40 130769.20
prot 8-1536.0-1.3 2275222.40 89637.06 ( -12.09 )
detect 8-1536.0-1.3 2365008.40 124412.55 ( -8.62 )
base 8-1792.0-0.1 43328279.20 946469.12
prot 8-1792.0-0.1 41481980.80 525690.89 ( -4.26 )
detect 8-1792.0-0.1 41713944.60 406798.93 ( -3.73 )
base 8-1792.0-0.7 27155647.40 536253.57
prot 8-1792.0-0.7 24989406.80 502734.52 ( -7.98 )
detect 8-1792.0-0.7 25524806.40 263237.87 ( -6.01 )
base 8-1792.0-1.3 3260372.80 137907.92
prot 8-1792.0-1.3 2879187.80 63597.26 ( -11.69 )
detect 8-1792.0-1.3 2892962.20 33229.13 ( -11.27 )
base 8-2048.0-0.1 50583989.80 710121.48
prot 8-2048.0-0.1 49599984.40 228782.42 ( -1.95 )
detect 8-2048.0-0.1 50578596.00 660971.66 ( -0.01 )
base 8-2048.0-0.7 33765479.60 812659.55
prot 8-2048.0-0.7 30767021.20 462907.24 ( -8.88 )
detect 8-2048.0-0.7 32213068.80 211884.24 ( -4.60 )
base 8-2048.0-1.3 3941675.80 28436.45
prot 8-2048.0-1.3 3538742.40 76856.08 ( -10.22 )
detect 8-2048.0-1.3 3579397.80 58630.95 ( -9.19 )
As we can see, all the cases show improvement. Especially, test case with
zipf distribution 1.3 show more improvements. It means that if there is a
hot/cold tendency in anon pages, this patchset works better.
This patch (of 6):
Current implementation of LRU management for anonymous page has some
problems. Most important one is that it doesn't protect the workingset,
that is, pages on the active LRU list. Although, this problem will be
fixed in the following patchset, the preparation is required and this
patch does it.
What following patch does is to implement workingset protection. After
the following patchset, newly created or swap-in pages will start their
lifetime on the inactive list. If inactive list is too small, there is
not enough chance to be referenced and the page cannot become the
workingset.
In order to provide the newly anonymous or swap-in pages enough chance to
be referenced again, this patch makes active/inactive LRU ratio as 1:1.
This is just a temporary measure. Later patch in the series introduces
workingset detection for anonymous LRU that will be used to better decide
if pages should start on the active and inactive list. Afterwards this
patch is effectively reverted.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Matthew Wilcox <willy@infradead.org>
Link: http://lkml.kernel.org/r/1595490560-15117-1-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1595490560-15117-2-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
Shakeel Butt
|
912c05720f |
mm: vmscan: consistent update to pgrefill
The vmstat pgrefill is useful together with pgscan and pgsteal stats to measure the reclaim efficiency. However vmstat's pgrefill is not updated consistently at system level. It gets updated for both global and memcg reclaim however pgscan and pgsteal are updated for only global reclaim. So, update pgrefill only for global reclaim. If someone is interested in the stats representing both system level as well as memcg level reclaim, then consult the root memcg's memory.stat instead of /proc/vmstat. Signed-off-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Yafang Shao <laoar.shao@gmail.com> Acked-by: Roman Gushchin <guro@fb.com> Acked-by: Chris Down <chris@chrisdown.name> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Link: http://lkml.kernel.org/r/20200711011459.1159929-1-shakeelb@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
dylan-meiners
|
238c30468f |
mm/vmscan.c: fix typo
Change "optizimation" to "optimization". Signed-off-by: dylan-meiners <spacct.spacct@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: David Hildenbrand <david@redhat.com> Link: http://lkml.kernel.org/r/20200609185144.10049-1-spacct.spacct@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
David Hildenbrand
|
0a18e60788 |
mm: remove vm_total_pages
The global variable "vm_total_pages" is a relic from older days. There is only a single user that reads the variable - build_all_zonelists() - and the first thing it does is update it. Use a local variable in build_all_zonelists() instead and remove the global variable. Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Huang Ying <ying.huang@intel.com> Cc: Minchan Kim <minchan@kernel.org> Link: http://lkml.kernel.org/r/20200619132410.23859-2-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
Johannes Weiner
|
e22c6ed90a |
mm: memcontrol: don't count limit-setting reclaim as memory pressure
When an outside process lowers one of the memory limits of a cgroup (or uses the force_empty knob in cgroup1), direct reclaim is performed in the context of the write(), in order to directly enforce the new limit and have it being met by the time the write() returns. Currently, this reclaim activity is accounted as memory pressure in the cgroup that the writer(!) belongs to. This is unexpected. It specifically causes problems for senpai (https://github.com/facebookincubator/senpai), which is an agent that routinely adjusts the memory limits and performs associated reclaim work in tens or even hundreds of cgroups running on the host. The cgroup that senpai is running in itself will report elevated levels of memory pressure, even though it itself is under no memory shortage or any sort of distress. Move the psi annotation from the central cgroup reclaim function to callsites in the allocation context, and thereby no longer count any limit-setting reclaim as memory pressure. If the newly set limit causes the workload inside the cgroup into direct reclaim, that of course will continue to count as memory pressure. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Shakeel Butt <shakeelb@google.com> Reviewed-by: Roman Gushchin <guro@fb.com> Acked-by: Chris Down <chris@chrisdown.name> Acked-by: Michal Hocko <mhocko@suse.com> Link: http://lkml.kernel.org/r/20200728135210.379885-2-hannes@cmpxchg.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
Chris Down
|
45c7f7e1ef |
mm, memcg: decouple e{low,min} state mutations from protection checks
mem_cgroup_protected currently is both used to set effective low and min and return a mem_cgroup_protection based on the result. As a user, this can be a little unexpected: it appears to be a simple predicate function, if not for the big warning in the comment above about the order in which it must be executed. This change makes it so that we separate the state mutations from the actual protection checks, which makes it more obvious where we need to be careful mutating internal state, and where we are simply checking and don't need to worry about that. [mhocko@suse.com - don't check protection on root memcgs] Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Chris Down <chris@chrisdown.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Roman Gushchin <guro@fb.com> Cc: Yafang Shao <laoar.shao@gmail.com> Link: http://lkml.kernel.org/r/ff3f915097fcee9f6d7041c084ef92d16aaeb56a.1594638158.git.chris@chrisdown.name Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
Yafang Shao
|
22f7496f0b |
mm, memcg: avoid stale protection values when cgroup is above protection
Patch series "mm, memcg: memory.{low,min} reclaim fix & cleanup", v4.
This series contains a fix for a edge case in my earlier protection
calculation patches, and a patch to make the area overall a little more
robust to hopefully help avoid this in future.
This patch (of 2):
A cgroup can have both memory protection and a memory limit to isolate it
from its siblings in both directions - for example, to prevent it from
being shrunk below 2G under high pressure from outside, but also from
growing beyond 4G under low pressure.
Commit
|
||
Roman Gushchin
|
d42f3245c7 |
mm: memcg: convert vmstat slab counters to bytes
In order to prepare for per-object slab memory accounting, convert NR_SLAB_RECLAIMABLE and NR_SLAB_UNRECLAIMABLE vmstat items to bytes. To make it obvious, rename them to NR_SLAB_RECLAIMABLE_B and NR_SLAB_UNRECLAIMABLE_B (similar to NR_KERNEL_STACK_KB). Internally global and per-node counters are stored in pages, however memcg and lruvec counters are stored in bytes. This scheme may look weird, but only for now. As soon as slab pages will be shared between multiple cgroups, global and node counters will reflect the total number of slab pages. However memcg and lruvec counters will be used for per-memcg slab memory tracking, which will take separate kernel objects in the account. Keeping global and node counters in pages helps to avoid additional overhead. The size of slab memory shouldn't exceed 4Gb on 32-bit machines, so it will fit into atomic_long_t we use for vmstats. Signed-off-by: Roman Gushchin <guro@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/20200623174037.3951353-4-guro@fb.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Johannes Weiner
|
31d8fcac00 |
mm: workingset: age nonresident information alongside anonymous pages
Patch series "fix for "mm: balance LRU lists based on relative
thrashing" patchset"
This patchset fixes some problems of the patchset, "mm: balance LRU
lists based on relative thrashing", which is now merged on the mainline.
Patch "mm: workingset: let cache workingset challenge anon fix" is the
result of discussion with Johannes. See following link.
http://lkml.kernel.org/r/20200520232525.798933-6-hannes@cmpxchg.org
And, the other two are minor things which are found when I try to rebase
my patchset.
This patch (of 3):
After ("mm: workingset: let cache workingset challenge anon fix"), we
compare refault distances to active_file + anon. But age of the
non-resident information is only driven by the file LRU. As a result,
we may overestimate the recency of any incoming refaults and activate
them too eagerly, causing unnecessary LRU churn in certain situations.
Make anon aging drive nonresident age as well to address that.
Link: http://lkml.kernel.org/r/1592288204-27734-1-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1592288204-27734-2-git-send-email-iamjoonsoo.kim@lge.com
Fixes:
|
||
Ethon Paul
|
55b65a57c2 |
mm/vmsan: fix some typos in comment
There are some typos, fix them. s/regsitration/registration s/santity/sanity s/decremeting/decrementing Signed-off-by: Ethon Paul <ethp@qq.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Link: http://lkml.kernel.org/r/20200411071544.16222-1-ethp@qq.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Johannes Weiner
|
d483a5dd00 |
mm: vmscan: limit the range of LRU type balancing
When LRU cost only shows up on one list, we abruptly stop scanning that list altogether. That's an extreme reaction: by the time the other list starts thrashing and the pendulum swings back, we may have no recent age information on the first list anymore, and we could have significant latencies until the scanner has caught up. Soften this change in the feedback system by ensuring that no list receives less than a third of overall pressure, and only distribute the other 66% according to LRU cost. This ensures that we maintain a minimum rate of aging on the entire workingset while it's being pressured, while still allowing a generous rate of convergence when the relative sizes of the lists need to adjust. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@surriel.com> Link: http://lkml.kernel.org/r/20200520232525.798933-15-hannes@cmpxchg.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Johannes Weiner
|
96f8bf4fb1 |
mm: vmscan: reclaim writepage is IO cost
The VM tries to balance reclaim pressure between anon and file so as to reduce the amount of IO incurred due to the memory shortage. It already counts refaults and swapins, but in addition it should also count writepage calls during reclaim. For swap, this is obvious: it's IO that wouldn't have occurred if the anonymous memory hadn't been under memory pressure. From a relative balancing point of view this makes sense as well: even if anon is cold and reclaimable, a cache that isn't thrashing may have equally cold pages that don't require IO to reclaim. For file writeback, it's trickier: some of the reclaim writepage IO would have likely occurred anyway due to dirty expiration. But not all of it - premature writeback reduces batching and generates additional writes. Since the flushers are already woken up by the time the VM starts writing cache pages one by one, let's assume that we'e likely causing writes that wouldn't have happened without memory pressure. In addition, the per-page cost of IO would have probably been much cheaper if written in larger batches from the flusher thread rather than the single-page-writes from kswapd. For our purposes - getting the trend right to accelerate convergence on a stable state that doesn't require paging at all - this is sufficiently accurate. If we later wanted to optimize for sustained thrashing, we can still refine the measurements. Count all writepage calls from kswapd as IO cost toward the LRU that the page belongs to. Why do this dynamically? Don't we know in advance that anon pages require IO to reclaim, and so could build in a static bias? First, scanning is not the same as reclaiming. If all the anon pages are referenced, we may not swap for a while just because we're scanning the anon list. During this time, however, it's important that we age anonymous memory and the page cache at the same rate so that their hot-cold gradients are comparable. Everything else being equal, we still want to reclaim the coldest memory overall. Second, we keep copies in swap unless the page changes. If there is swap-backed data that's mostly read (tmpfs file) and has been swapped out before, we can reclaim it without incurring additional IO. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@surriel.com> Link: http://lkml.kernel.org/r/20200520232525.798933-14-hannes@cmpxchg.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Johannes Weiner
|
7cf111bc39 |
mm: vmscan: determine anon/file pressure balance at the reclaim root
We split the LRU lists into anon and file, and we rebalance the scan pressure between them when one of them begins thrashing: if the file cache experiences workingset refaults, we increase the pressure on anonymous pages; if the workload is stalled on swapins, we increase the pressure on the file cache instead. With cgroups and their nested LRU lists, we currently don't do this correctly. While recursive cgroup reclaim establishes a relative LRU order among the pages of all involved cgroups, LRU pressure balancing is done on an individual cgroup LRU level. As a result, when one cgroup is thrashing on the filesystem cache while a sibling may have cold anonymous pages, pressure doesn't get equalized between them. This patch moves LRU balancing decision to the root of reclaim - the same level where the LRU order is established. It does this by tracking LRU cost recursively, so that every level of the cgroup tree knows the aggregate LRU cost of all memory within its domain. When the page scanner calculates the scan balance for any given individual cgroup's LRU list, it uses the values from the ancestor cgroup that initiated the reclaim cycle. If one sibling is then thrashing on the cache, it will tip the pressure balance inside its ancestors, and the next hierarchical reclaim iteration will go more after the anon pages in the tree. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@surriel.com> Link: http://lkml.kernel.org/r/20200520232525.798933-13-hannes@cmpxchg.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Johannes Weiner
|
314b57fb04 |
mm: balance LRU lists based on relative thrashing
Since the LRUs were split into anon and file lists, the VM has been
balancing between page cache and anonymous pages based on per-list ratios
of scanned vs. rotated pages. In most cases that tips page reclaim
towards the list that is easier to reclaim and has the fewest actively
used pages, but there are a few problems with it:
1. Refaults and LRU rotations are weighted the same way, even though
one costs IO and the other costs a bit of CPU.
2. The less we scan an LRU list based on already observed rotations,
the more we increase the sampling interval for new references, and
rotations become even more likely on that list. This can enter a
death spiral in which we stop looking at one list completely until
the other one is all but annihilated by page reclaim.
Since commit
|
||
|
Johannes Weiner
|
264e90cc07 |
mm: only count actual rotations as LRU reclaim cost
When shrinking the active file list we rotate referenced pages only when they're in an executable mapping. The others get deactivated. When it comes to balancing scan pressure, though, we count all referenced pages as rotated, even the deactivated ones. Yet they do not carry the same cost to the system: the deactivated page *might* refault later on, but the deactivation is tangible progress toward freeing pages; rotations on the other hand cost time and effort without getting any closer to freeing memory. Don't treat both events as equal. The following patch will hook up LRU balancing to cache and anon refaults, which are a much more concrete cost signal for reclaiming one list over the other. Thus, remove the maybe-IO cost bias from page references, and only note the CPU cost for actual rotations that prevent the pages from getting reclaimed. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Minchan Kim <minchan@kernel.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Rik van Riel <riel@surriel.com> Link: http://lkml.kernel.org/r/20200520232525.798933-11-hannes@cmpxchg.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Johannes Weiner
|
1431d4d11a |
mm: base LRU balancing on an explicit cost model
Currently, scan pressure between the anon and file LRU lists is balanced based on a mixture of reclaim efficiency and a somewhat vague notion of "value" of having certain pages in memory over others. That concept of value is problematic, because it has caused us to count any event that remotely makes one LRU list more or less preferrable for reclaim, even when these events are not directly comparable and impose very different costs on the system. One example is referenced file pages that we still deactivate and referenced anonymous pages that we actually rotate back to the head of the list. There is also conceptual overlap with the LRU algorithm itself. By rotating recently used pages instead of reclaiming them, the algorithm already biases the applied scan pressure based on page value. Thus, when rebalancing scan pressure due to rotations, we should think of reclaim cost, and leave assessing the page value to the LRU algorithm. Lastly, considering both value-increasing as well as value-decreasing events can sometimes cause the same type of event to be counted twice, i.e. how rotating a page increases the LRU value, while reclaiming it succesfully decreases the value. In itself this will balance out fine, but it quietly skews the impact of events that are only recorded once. The abstract metric of "value", the murky relationship with the LRU algorithm, and accounting both negative and positive events make the current pressure balancing model hard to reason about and modify. This patch switches to a balancing model of accounting the concrete, actually observed cost of reclaiming one LRU over another. For now, that cost includes pages that are scanned but rotated back to the list head. Subsequent patches will add consideration for IO caused by refaulting of recently evicted pages. Replace struct zone_reclaim_stat with two cost counters in the lruvec, and make everything that affects cost go through a new lru_note_cost() function. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@surriel.com> Link: http://lkml.kernel.org/r/20200520232525.798933-9-hannes@cmpxchg.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Johannes Weiner
|
a4fe1631f3 |
mm: vmscan: drop unnecessary div0 avoidance rounding in get_scan_count()
When we calculate the relative scan pressure between the anon and file LRU
lists, we have to assume that reclaim_stat can contain zeroes. To avoid
div0 crashes, we add 1 to all denominators like so:
anon_prio = swappiness;
file_prio = 200 - anon_prio;
[...]
/*
* The amount of pressure on anon vs file pages is inversely
* proportional to the fraction of recently scanned pages on
* each list that were recently referenced and in active use.
*/
ap = anon_prio * (reclaim_stat->recent_scanned[0] + 1);
ap /= reclaim_stat->recent_rotated[0] + 1;
fp = file_prio * (reclaim_stat->recent_scanned[1] + 1);
fp /= reclaim_stat->recent_rotated[1] + 1;
spin_unlock_irq(&pgdat->lru_lock);
fraction[0] = ap;
fraction[1] = fp;
denominator = ap + fp + 1;
While reclaim_stat can contain 0, it's not actually possible for ap + fp
to be 0. One of anon_prio or file_prio could be zero, but they must still
add up to 200. And the reclaim_stat fraction, due to the +1 in there, is
always at least 1. So if one of the two numerators is 0, the other one
can't be. ap + fp is always at least 1. Drop the + 1.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/20200520232525.798933-8-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
Johannes Weiner
|
c843966c55 |
mm: allow swappiness that prefers reclaiming anon over the file workingset
With the advent of fast random IO devices (SSDs, PMEM) and in-memory swap devices such as zswap, it's possible for swap to be much faster than filesystems, and for swapping to be preferable over thrashing filesystem caches. Allow setting swappiness - which defines the rough relative IO cost of cache misses between page cache and swap-backed pages - to reflect such situations by making the swap-preferred range configurable. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@surriel.com> Link: http://lkml.kernel.org/r/20200520232525.798933-4-hannes@cmpxchg.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Johannes Weiner
|
497a6c1b09 |
mm: keep separate anon and file statistics on page reclaim activity
Having statistics on pages scanned and pages reclaimed for both anon and file pages makes it easier to evaluate changes to LRU balancing. While at it, clean up the stat-keeping mess for isolation, putback, reclaim stats etc. a bit: first the physical LRU operation (isolation and putback), followed by vmstats, reclaim_stats, and then vm events. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@surriel.com> Link: http://lkml.kernel.org/r/20200520232525.798933-3-hannes@cmpxchg.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Qiwu Chen
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df3a45f9d8 |
mm/vmscan: update the comment of should_continue_reclaim()
try_to_compact_zone() has been replaced by try_to_compact_pages(), which is necessary to be updated in the comment of should_continue_reclaim(). Signed-off-by: Qiwu Chen <chenqiwu@xiaomi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200501034907.22991-1-chenqiwu@xiaomi.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Maninder Singh
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730ec8c01a |
mm/vmscan.c: change prototype for shrink_page_list
commit
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Jaewon Kim
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1f318a9b0d |
mm/vmscan: count layzfree pages and fix nr_isolated_* mismatch
Fix an nr_isolate_* mismatch problem between cma and dirty lazyfree pages. If try_to_unmap_one is used for reclaim and it detects a dirty lazyfree page, then the lazyfree page is changed to a normal anon page having SwapBacked by commit |