end_migration() passes the old page instead of the new page to commit
the charge. This page descriptor is not used for committing itself,
though, since we also pass the (correct) page_cgroup descriptor. But
it's used to find the soft limit tree through the page's zone, so the
soft limit tree of the old page's zone is updated instead of that of the
new page's, which might get slightly out of date until the next charge
reaches the ratelimit point.
This glitch has been present since 5564e88 ("memcg: condense
page_cgroup-to-page lookup points").
This fixes a bug that I introduced in 2.6.38. It's benign enough (to my
knowledge) that we probably don't want this for stable.
Reported-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
/proc/pid/clear_refs is used to clear the Referenced and YOUNG bits for
pages and corresponding page table entries of the task with PID pid, which
includes any special mappings inserted into the page tables in order to
provide things like vDSOs and user helper functions.
On ARM this causes a problem because the vectors page is mapped as a
global mapping and since ec706dab ("ARM: add a vma entry for the user
accessible vector page"), a VMA is also inserted into each task for this
page to aid unwinding through signals and syscall restarts. Since the
vectors page is required for handling faults, clearing the YOUNG bit (and
subsequently writing a faulting pte) means that we lose the vectors page
*globally* and cannot fault it back in. This results in a system deadlock
on the next exception.
To see this problem in action, just run:
$ echo 1 > /proc/self/clear_refs
on an ARM platform (as any user) and watch your system hang. I think this
has been the case since 2.6.37
This patch avoids clearing the aforementioned bits for reserved pages,
therefore leaving the vectors page intact on ARM. Since reserved pages
are not candidates for swap, this change should not have any impact on the
usefulness of clear_refs.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Reported-by: Moussa Ba <moussaba@micron.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Acked-by: Nicolas Pitre <nico@linaro.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: <stable@vger.kernel.org> [2.6.37+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Alberto Panizzo <alberto@amarulasolutions.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We need to write new value if the bit mask fields of new value is not
equal to old value. It does not make sense to write new value only when
all the bit_mask bits are zero.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Cc: Michael Hennerich <michael.hennerich@analog.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit ef53d9c5e ("kprobes: improve kretprobe scalability with hashed
locking") introduced a bug where we can potentially leak
kretprobe_instances since we initialize a hlist head after having used
it.
Initialize the hlist head before using it.
Reported by: Jim Keniston <jkenisto@us.ibm.com>
Acked-by: Jim Keniston <jkenisto@us.ibm.com>
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Srinivasa D S <srinivasa@in.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Because the current task is being used to get the limit, we can simply
use rlimit() instead of task_rlimit().
Signed-off-by: Davidlohr Bueso <dave@gnu.org>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add support for leds on Bachmann's ot200 visualisation device. The
device has three leds on the back panel (led_err, led_init and led_run)
and can handle up to seven leds on the front panel.
The driver was written by Linutronix on behalf of Bachmann electronic
GmbH. It incorporates feedback from Lars-Peter Clausen
[akpm@linux-foundation.org: add dependency on HAS_IOMEM]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
page_zone() requires an online node otherwise we are accessing NULL
NODE_DATA. This is not an issue at the moment because node_zones are
located at the structure beginning but this might change in the future
so better be careful about that.
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix the following NULL ptr dereference caused by
cat /sys/devices/system/memory/memory0/removable
Pid: 13979, comm: sed Not tainted 3.0.13-0.5-default #1 IBM BladeCenter LS21 -[7971PAM]-/Server Blade
RIP: __count_immobile_pages+0x4/0x100
Process sed (pid: 13979, threadinfo ffff880221c36000, task ffff88022e788480)
Call Trace:
is_pageblock_removable_nolock+0x34/0x40
is_mem_section_removable+0x74/0xf0
show_mem_removable+0x41/0x70
sysfs_read_file+0xfe/0x1c0
vfs_read+0xc7/0x130
sys_read+0x53/0xa0
system_call_fastpath+0x16/0x1b
We are crashing because we are trying to dereference NULL zone which
came from pfn=0 (struct page ffffea0000000000). According to the boot
log this page is marked reserved:
e820 update range: 0000000000000000 - 0000000000010000 (usable) ==> (reserved)
and early_node_map confirms that:
early_node_map[3] active PFN ranges
1: 0x00000010 -> 0x0000009c
1: 0x00000100 -> 0x000bffa3
1: 0x00100000 -> 0x00240000
The problem is that memory_present works in PAGE_SECTION_MASK aligned
blocks so the reserved range sneaks into the the section as well. This
also means that free_area_init_node will not take care of those reserved
pages and they stay uninitialized.
When we try to read the removable status we walk through all available
sections and hope that the zone is valid for all pages in the section.
But this is not true in this case as the zone and nid are not initialized.
We have only one node in this particular case and it is marked as node=1
(rather than 0) and that made the problem visible because page_to_nid will
return 0 and there are no zones on the node.
Let's check that the zone is valid and that the given pfn falls into its
boundaries and mark the section not removable. This might cause some
false positives, probably, but we do not have any sane way to find out
whether the page is reserved by the platform or it is just not used for
whatever other reasons.
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sparc64 allmodconfig:
In file included from include/linux/compat.h:15,
from /usr/src/25/arch/sparc/include/asm/siginfo.h:19,
from include/linux/signal.h:5,
from include/linux/sched.h:73,
from arch/sparc/kernel/asm-offsets.c:13:
include/linux/fs.h:618: warning: parameter has incomplete type
It seems that my sparc64 compiler (gcc-3.4.5) doesn't like the forward
declaration of enums.
Fix this by moving the "enum migrate_mode" definition into its own header
file.
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andy Isaacson <adi@hexapodia.org>
Cc: Nai Xia <nai.xia@gmail.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The user reports that model=auto works fine for him. Using
model=auto bring in new features such as jack detection notification
to userspace.
Alsa info is available at http://paste.ubuntu.com/805351/
Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The commit 2ae66c2655
ALSA: hda: option to enable arbitrary buffer/period sizes
introduced a regression on machines with Intel controller and Nvidia
HDMI. The reason is that the driver modifies the global variable
align_buffer_size when an Intel controller is found, and the Nvidia
HDMI controller is probed after Intel although Nvidia chips require
the aligned buffers.
This patch fixes the problem by moving the flag into the local struct
so that it's not affected by other controllers.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=42567
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
In sis_driver_load(), the only use of 'ret' is as the return value
from the function, unfortunately it is never initialized, so the
function just returns garbage when it succeeds.
To fix that, remove the variable and just return 0 directly on success.
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
It doesn't seem right for the thermal subsystem to export a symbol
named generate_netlink_event. This function is thermal-specific and
its name should reflect that fact. Rename it to
thermal_generate_netlink_event.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: R.Durgadoss <durgadoss.r@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Allow ETHTOOL_GSSET_INFO ethtool ioctl() for unprivileged users.
ETHTOOL_GSTRINGS is already allowed, but is unusable without this one.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Acked-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fixes:
net/bluetooth/hci_core.c: In function ‘__check_enable_hs’:
net/bluetooth/hci_core.c:2587:1: warning: return from incompatible pointer type [enabled by default]
Signed-off-by: David S. Miller <davem@davemloft.net>
There is a case in __sk_mem_schedule(), where an allocation
is beyond the maximum, but yet we are allowed to proceed.
It happens under the following condition:
sk->sk_wmem_queued + size >= sk->sk_sndbuf
The network code won't revert the allocation in this case,
meaning that at some point later it'll try to do it. Since
this is never communicated to the underlying res_counter
code, there is an inbalance in res_counter uncharge operation.
I see two ways of fixing this:
1) storing the information about those allocations somewhere
in memcg, and then deducting from that first, before
we start draining the res_counter,
2) providing a slightly different allocation function for
the res_counter, that matches the original behavior of
the network code more closely.
I decided to go for #2 here, believing it to be more elegant,
since #1 would require us to do basically that, but in a more
obscure way.
Signed-off-by: Glauber Costa <glommer@parallels.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
CC: Tejun Heo <tj@kernel.org>
CC: Li Zefan <lizf@cn.fujitsu.com>
CC: Laurent Chavey <chavey@google.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
For the memcg sock code, we'll need to register allocations
that are temporarily over limit. Let's make sure that margin
is 0 in this case.
I am keeping this as a separate patch, so that if any weirdness
interaction appears in the future, we can now exactly what caused
it.
Suggested by Johannes Weiner
Signed-off-by: Glauber Costa <glommer@parallels.com>
CC: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
CC: Johannes Weiner <hannes@cmpxchg.org>
CC: Michal Hocko <mhocko@suse.cz>
CC: Tejun Heo <tj@kernel.org>
CC: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
There is still a build bug with the sock memcg code, that triggers
with !CONFIG_NET, that survived my series of randconfig builds.
Signed-off-by: Glauber Costa <glommer@parallels.com>
Reported-by: Randy Dunlap <rdunlap@xenotime.net>
CC: Hiroyouki Kamezawa <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix new kernel-doc warning:
Warning(include/net/sock.h:372): No description found for parameter 'sk_cgrp_prioidx'
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix new kernel-doc warning:
Warning(drivers/net/phy/mdio_bus.c:49): No description found for parameter 'size'
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
md5 key is added in socket through remote address.
remote address should be used in finding md5 key when
sending out reset packet.
Signed-off-by: shawnlu <shawn.lu@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently RSS rings are not created in a multi-channel config.
RSS rings can be created on one (out of four) interfaces per port in a
multi-channel config. Doing this insulates the driver from a FW bug wherin
multi-channel config is wrongly reported even when not enabled. This also
helps performance in a multi-channel config, as one interface per port gets
RSS rings.
Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Every call to num_args() immediately checks the return value for
less than zero, as it will return -EFAULT for a failed get_user()
call. So it makes no sense for the function to be declared as an
unsigned long.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Correctly implement a loss detection heuristic: New sequences (above
high_seq) sent during the fast recovery are deemed lost when higher
sequences are SACKed.
Current code does not catch these losses, because tcp_mark_head_lost()
does not check packets beyond high_seq. The fix is straight-forward by
checking packets until the highest sacked packet. In addition, all the
FLAG_DATA_LOST logic are in-effective and redundant and can be removed.
Update the loss heuristic comments. The algorithm above is documented
as heuristic B, but it is redundant too because heuristic A already
covers B.
Note that this change only marks some forward-retransmitted packets LOST.
It does NOT forbid TCP performing further CWR on new losses. A potential
follow-up patch under preparation is to perform another CWR on "new"
losses such as
1) sequence above high_seq is lost (by resetting high_seq to snd_nxt)
2) retransmission is lost.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Driver should check for mapping errors.
Machines with limited DMA maps may return an error when a PCI map is
requested (not an issue on standard x86).
Also use upper/lower 32 bits macros for clarity.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Skge device would assert carrier (link up) as soon as network device open
was called, rather than waiting until PHY has detected link.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
With netem reordering, a gap of N is supposed to reorder every Nth packet with
given reorder probability. However, the code currently skips N packets and
reorders every (N+1)th packet.
Signed-off-by: Vijay Subramanian <subramanian.vijay@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Slave async events were mapped to single eq. This patch fixes this issue, so
the slaves can map the async events to any eq.
Signed-off-by: Marcel Apfelbaum <marcela@dev.mellanox.co.il>
Reviewed-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>
Num mtts from profile is really the number of mtt segments.
Thus, in make profile, to get the proper number of MTT entries,
must multiply num_mtts by mtts per segment.
Signed-off-by: Marcel Apfelbaum <marcela@dev.mellanox.co.il>
Reviewed-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>
The Virtual Functions should not be aware their function number.
Signed-off-by: Marcel Apfelbaum <marcela@dev.mellanox.co.il>
Reviewed-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>
In native mode display all available staticstics.
In SRIOV mode on VF display only SW counters statistics,
in SRIOV mode on hypervisor display SW counters and errors (got from FW)
statistics.
Signed-off-by: Eugenia Emantayev <eugenia@mellanox.co.il>
Reviewed-by: Yevgeny Petrilin <yevgenyp@mellanox.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>
In multifunction mode - DUMP_STATS command is not executed
for VFs.
Signed-off-by: Eugenia Emantayev <eugenia@mellanox.co.il>
Reviewed-by: Yevgeny Petrilin <yevgenyp@mellanox.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>
Bug fix: Not all stats fields were cleared.
Signed-off-by: Eugenia Emantayev <eugenia@mellanox.co.il>
Reviewed-by: Yevgeny Petriln <yevgenyp@mellanox.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>
We should be allowing a 5ms delay after the charge pump is started in
order to ensure it has finished ramping.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@kernel.org
Passing the address of a variable as an operand to an asm statement
doesn't mark the value of this variable as used, so gcc may optimize its
initialisation away. Fix this by using the "m" constraint instead.
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@vger.kernel.org
Rename the "Mac ESP" irq as "ESP" to be consistent with all the other Mac
drivers and ESP drivers.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Don't enable the SCSI irq when initialising the chip -- the irq has no
handler yet.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
macfb won't init in black & white modes since fb_alloc_cmap() no longer
works for zero cmap length. Fix this and also clean up a few printk's and
some stylistic inconsistencies.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
The perf_event_time() will call perf_cgroup_event_time()
if @event is a cgroup event. Just do it directly and avoid
the extra check..
Signed-off-by: Namhyung Kim <namhyung.kim@lge.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Link: http://lkml.kernel.org/r/1327021966-27688-2-git-send-email-namhyung.kim@lge.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When alloc_callchain_buffers() fails, it frees all of
entries before return. In addition, calling the
release_callchain_buffers() will cause a NULL pointer
dereference since callchain_cpu_entries is not set.
Signed-off-by: Namhyung Kim <namhyung.kim@lge.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Link: http://lkml.kernel.org/r/1327021966-27688-1-git-send-email-namhyung.kim@lge.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Sony Vaio VPCCW29FX does not resume correctly without
acpi_sleep=nonvs, so add it to the ACPI sleep blacklist.
https://bugzilla.kernel.org/show_bug.cgi?id=34722
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
With the conversion of atomicio's routines in place (see commits
6f68c91c55 and 700130b41f), atomicio.[ch] can be removed, replacing
the APEI specific pre-mapping capabilities with the more generalized
versions that drivers/acpi/osl.c provides.
Signed-off-by: Myron Stowe <myron.stowe@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This patch adds support for RAM to ACPI's mapping capabilities in order
to support APEI error injection (EINJ) actions.
This patch re-factors similar functionality introduced in commit
76da3fb357, bringing it into osl.c in preparation for removing
./drivers/acpi/atomicio.[ch].
Signed-off-by: Myron Stowe <myron.stowe@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Base ACPI (CA) currently does not support atomic 64-bit reads and writes
(acpi_read() and acpi_write() split 64-bit loads/stores into two
32-bit transfers) yet APEI expects 64-bit transfer capability, even
when running on 32-bit systems.
This patch implements 64-bit read and write routines for APEI usage.
This patch re-factors similar functionality introduced in commit
04c25997c9, bringing it into the ACPI subsystem in preparation for
removing ./drivers/acpi/atomicio.[ch]. In the implementation I have
replicated acpi_os_read_memory() and acpi_os_write_memory(), creating
64-bit versions for APEI to utilize, as opposed to something more
elegant. My thinking is that we should attempt to see if we can get
ACPI's CA/OSL changed so that the existing acpi_read() and acpi_write()
interfaces are natively 64-bit capable and then subsequently remove the
replication.
Signed-off-by: Myron Stowe <myron.stowe@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This patch fixes CUBIC so that cwnd reductions made during RTOs can be
undone (just as they already can be undone when using the default/Reno
behavior).
When undoing cwnd reductions, BIC-derived congestion control modules
were restoring the cwnd from last_max_cwnd. There were two problems
with using last_max_cwnd to restore a cwnd during undo:
(a) last_max_cwnd was set to 0 on state transitions into TCP_CA_Loss
(by calling the module's reset() functions), so cwnd reductions from
RTOs could not be undone.
(b) when fast_covergence is enabled (which it is by default)
last_max_cwnd does not actually hold the value of snd_cwnd before the
loss; instead, it holds a scaled-down version of snd_cwnd.
This patch makes the following changes:
(1) upon undo, revert snd_cwnd to ca->loss_cwnd, which is already, as
the existing comment notes, the "congestion window at last loss"
(2) stop forgetting ca->loss_cwnd on TCP_CA_Loss events
(3) use ca->last_max_cwnd to check if we're in slow start
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Sangtae Ha <sangtae.ha@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch fixes BIC so that cwnd reductions made during RTOs can be
undone (just as they already can be undone when using the default/Reno
behavior).
When undoing cwnd reductions, BIC-derived congestion control modules
were restoring the cwnd from last_max_cwnd. There were two problems
with using last_max_cwnd to restore a cwnd during undo:
(a) last_max_cwnd was set to 0 on state transitions into TCP_CA_Loss
(by calling the module's reset() functions), so cwnd reductions from
RTOs could not be undone.
(b) when fast_covergence is enabled (which it is by default)
last_max_cwnd does not actually hold the value of snd_cwnd before the
loss; instead, it holds a scaled-down version of snd_cwnd.
This patch makes the following changes:
(1) upon undo, revert snd_cwnd to ca->loss_cwnd, which is already, as
the existing comment notes, the "congestion window at last loss"
(2) stop forgetting ca->loss_cwnd on TCP_CA_Loss events
(3) use ca->last_max_cwnd to check if we're in slow start
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
