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1455083c1d
Patch series "make vm_committed_as_batch aware of vm overcommit policy", v6. When checking a performance change for will-it-scale scalability mmap test [1], we found very high lock contention for spinlock of percpu counter 'vm_committed_as': 94.14% 0.35% [kernel.kallsyms] [k] _raw_spin_lock_irqsave 48.21% _raw_spin_lock_irqsave;percpu_counter_add_batch;__vm_enough_memory;mmap_region;do_mmap; 45.91% _raw_spin_lock_irqsave;percpu_counter_add_batch;__do_munmap; Actually this heavy lock contention is not always necessary. The 'vm_committed_as' needs to be very precise when the strict OVERCOMMIT_NEVER policy is set, which requires a rather small batch number for the percpu counter. So keep 'batch' number unchanged for strict OVERCOMMIT_NEVER policy, and enlarge it for not-so-strict OVERCOMMIT_ALWAYS and OVERCOMMIT_GUESS policies. Benchmark with the same testcase in [1] shows 53% improvement on a 8C/16T desktop, and 2097%(20X) on a 4S/72C/144T server. And for that case, whether it shows improvements depends on if the test mmap size is bigger than the batch number computed. We tested 10+ platforms in 0day (server, desktop and laptop). If we lift it to 64X, 80%+ platforms show improvements, and for 16X lift, 1/3 of the platforms will show improvements. And generally it should help the mmap/unmap usage,as Michal Hocko mentioned: : I believe that there are non-synthetic worklaods which would benefit : from a larger batch. E.g. large in memory databases which do large : mmaps during startups from multiple threads. Note: There are some style complain from checkpatch for patch 4, as sysctl handler declaration follows the similar format of sibling functions [1] https://lore.kernel.org/lkml/20200305062138.GI5972@shao2-debian/ This patch (of 4): Use the existing vm_memory_committed() instead, which is also convenient for future change. Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Qian Cai <cai@lca.pw> Cc: Kees Cook <keescook@chromium.org> Cc: Andi Kleen <andi.kleen@intel.com> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: kernel test robot <rong.a.chen@intel.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/1594389708-60781-1-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1594389708-60781-2-git-send-email-feng.tang@intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
162 lines
5.2 KiB
C
162 lines
5.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/fs.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/hugetlb.h>
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#include <linux/mman.h>
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#include <linux/mmzone.h>
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#include <linux/proc_fs.h>
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#include <linux/percpu.h>
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#include <linux/seq_file.h>
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#include <linux/swap.h>
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#include <linux/vmstat.h>
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#include <linux/atomic.h>
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#include <linux/vmalloc.h>
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#ifdef CONFIG_CMA
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#include <linux/cma.h>
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#endif
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#include <asm/page.h>
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#include "internal.h"
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void __attribute__((weak)) arch_report_meminfo(struct seq_file *m)
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{
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}
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static void show_val_kb(struct seq_file *m, const char *s, unsigned long num)
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{
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seq_put_decimal_ull_width(m, s, num << (PAGE_SHIFT - 10), 8);
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seq_write(m, " kB\n", 4);
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}
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static int meminfo_proc_show(struct seq_file *m, void *v)
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{
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struct sysinfo i;
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unsigned long committed;
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long cached;
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long available;
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unsigned long pages[NR_LRU_LISTS];
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unsigned long sreclaimable, sunreclaim;
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int lru;
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si_meminfo(&i);
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si_swapinfo(&i);
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committed = vm_memory_committed();
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cached = global_node_page_state(NR_FILE_PAGES) -
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total_swapcache_pages() - i.bufferram;
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if (cached < 0)
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cached = 0;
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for (lru = LRU_BASE; lru < NR_LRU_LISTS; lru++)
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pages[lru] = global_node_page_state(NR_LRU_BASE + lru);
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available = si_mem_available();
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sreclaimable = global_node_page_state_pages(NR_SLAB_RECLAIMABLE_B);
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sunreclaim = global_node_page_state_pages(NR_SLAB_UNRECLAIMABLE_B);
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show_val_kb(m, "MemTotal: ", i.totalram);
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show_val_kb(m, "MemFree: ", i.freeram);
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show_val_kb(m, "MemAvailable: ", available);
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show_val_kb(m, "Buffers: ", i.bufferram);
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show_val_kb(m, "Cached: ", cached);
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show_val_kb(m, "SwapCached: ", total_swapcache_pages());
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show_val_kb(m, "Active: ", pages[LRU_ACTIVE_ANON] +
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pages[LRU_ACTIVE_FILE]);
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show_val_kb(m, "Inactive: ", pages[LRU_INACTIVE_ANON] +
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pages[LRU_INACTIVE_FILE]);
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show_val_kb(m, "Active(anon): ", pages[LRU_ACTIVE_ANON]);
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show_val_kb(m, "Inactive(anon): ", pages[LRU_INACTIVE_ANON]);
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show_val_kb(m, "Active(file): ", pages[LRU_ACTIVE_FILE]);
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show_val_kb(m, "Inactive(file): ", pages[LRU_INACTIVE_FILE]);
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show_val_kb(m, "Unevictable: ", pages[LRU_UNEVICTABLE]);
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show_val_kb(m, "Mlocked: ", global_zone_page_state(NR_MLOCK));
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#ifdef CONFIG_HIGHMEM
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show_val_kb(m, "HighTotal: ", i.totalhigh);
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show_val_kb(m, "HighFree: ", i.freehigh);
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show_val_kb(m, "LowTotal: ", i.totalram - i.totalhigh);
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show_val_kb(m, "LowFree: ", i.freeram - i.freehigh);
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#endif
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#ifndef CONFIG_MMU
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show_val_kb(m, "MmapCopy: ",
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(unsigned long)atomic_long_read(&mmap_pages_allocated));
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#endif
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show_val_kb(m, "SwapTotal: ", i.totalswap);
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show_val_kb(m, "SwapFree: ", i.freeswap);
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show_val_kb(m, "Dirty: ",
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global_node_page_state(NR_FILE_DIRTY));
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show_val_kb(m, "Writeback: ",
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global_node_page_state(NR_WRITEBACK));
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show_val_kb(m, "AnonPages: ",
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global_node_page_state(NR_ANON_MAPPED));
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show_val_kb(m, "Mapped: ",
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global_node_page_state(NR_FILE_MAPPED));
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show_val_kb(m, "Shmem: ", i.sharedram);
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show_val_kb(m, "KReclaimable: ", sreclaimable +
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global_node_page_state(NR_KERNEL_MISC_RECLAIMABLE));
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show_val_kb(m, "Slab: ", sreclaimable + sunreclaim);
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show_val_kb(m, "SReclaimable: ", sreclaimable);
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show_val_kb(m, "SUnreclaim: ", sunreclaim);
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seq_printf(m, "KernelStack: %8lu kB\n",
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global_node_page_state(NR_KERNEL_STACK_KB));
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#ifdef CONFIG_SHADOW_CALL_STACK
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seq_printf(m, "ShadowCallStack:%8lu kB\n",
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global_node_page_state(NR_KERNEL_SCS_KB));
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#endif
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show_val_kb(m, "PageTables: ",
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global_zone_page_state(NR_PAGETABLE));
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show_val_kb(m, "NFS_Unstable: ", 0);
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show_val_kb(m, "Bounce: ",
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global_zone_page_state(NR_BOUNCE));
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show_val_kb(m, "WritebackTmp: ",
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global_node_page_state(NR_WRITEBACK_TEMP));
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show_val_kb(m, "CommitLimit: ", vm_commit_limit());
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show_val_kb(m, "Committed_AS: ", committed);
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seq_printf(m, "VmallocTotal: %8lu kB\n",
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(unsigned long)VMALLOC_TOTAL >> 10);
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show_val_kb(m, "VmallocUsed: ", vmalloc_nr_pages());
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show_val_kb(m, "VmallocChunk: ", 0ul);
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show_val_kb(m, "Percpu: ", pcpu_nr_pages());
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#ifdef CONFIG_MEMORY_FAILURE
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seq_printf(m, "HardwareCorrupted: %5lu kB\n",
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atomic_long_read(&num_poisoned_pages) << (PAGE_SHIFT - 10));
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#endif
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#ifdef CONFIG_TRANSPARENT_HUGEPAGE
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show_val_kb(m, "AnonHugePages: ",
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global_node_page_state(NR_ANON_THPS) * HPAGE_PMD_NR);
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show_val_kb(m, "ShmemHugePages: ",
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global_node_page_state(NR_SHMEM_THPS) * HPAGE_PMD_NR);
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show_val_kb(m, "ShmemPmdMapped: ",
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global_node_page_state(NR_SHMEM_PMDMAPPED) * HPAGE_PMD_NR);
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show_val_kb(m, "FileHugePages: ",
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global_node_page_state(NR_FILE_THPS) * HPAGE_PMD_NR);
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show_val_kb(m, "FilePmdMapped: ",
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global_node_page_state(NR_FILE_PMDMAPPED) * HPAGE_PMD_NR);
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#endif
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#ifdef CONFIG_CMA
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show_val_kb(m, "CmaTotal: ", totalcma_pages);
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show_val_kb(m, "CmaFree: ",
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global_zone_page_state(NR_FREE_CMA_PAGES));
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#endif
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hugetlb_report_meminfo(m);
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arch_report_meminfo(m);
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return 0;
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}
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static int __init proc_meminfo_init(void)
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{
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proc_create_single("meminfo", 0, NULL, meminfo_proc_show);
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return 0;
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}
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fs_initcall(proc_meminfo_init);
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