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c1b8fdae62
cgroup_memory_noswap is used in many hot path, so make it a static key
to lower the kernel overhead.
Using 8G of ZRAM as SWAP, benchmark using `perf stat -d -d -d --repeat 100`
with the following code snip in a non-root cgroup:
#include <stdio.h>
#include <string.h>
#include <linux/mman.h>
#include <sys/mman.h>
#define MB 1024UL * 1024UL
int main(int argc, char **argv){
void *p = mmap(NULL, 8000 * MB, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
memset(p, 0xff, 8000 * MB);
madvise(p, 8000 * MB, MADV_PAGEOUT);
memset(p, 0xff, 8000 * MB);
return 0;
}
Before:
7,021.43 msec task-clock # 0.967 CPUs utilized ( +- 0.03% )
4,010 context-switches # 573.853 /sec ( +- 0.01% )
0 cpu-migrations # 0.000 /sec
2,052,057 page-faults # 293.661 K/sec ( +- 0.00% )
12,616,546,027 cycles # 1.805 GHz ( +- 0.06% ) (39.92%)
156,823,666 stalled-cycles-frontend # 1.25% frontend cycles idle ( +- 0.10% ) (40.25%)
310,130,812 stalled-cycles-backend # 2.47% backend cycles idle ( +- 4.39% ) (40.73%)
18,692,516,591 instructions # 1.49 insn per cycle
# 0.01 stalled cycles per insn ( +- 0.04% ) (40.75%)
4,907,447,976 branches # 702.283 M/sec ( +- 0.05% ) (40.30%)
13,002,578 branch-misses # 0.26% of all branches ( +- 0.08% ) (40.48%)
7,069,786,296 L1-dcache-loads # 1.012 G/sec ( +- 0.03% ) (40.32%)
649,385,847 L1-dcache-load-misses # 9.13% of all L1-dcache accesses ( +- 0.07% ) (40.10%)
1,485,448,688 L1-icache-loads # 212.576 M/sec ( +- 0.15% ) (39.49%)
31,628,457 L1-icache-load-misses # 2.13% of all L1-icache accesses ( +- 0.40% ) (39.57%)
6,667,311 dTLB-loads # 954.129 K/sec ( +- 0.21% ) (39.50%)
5,668,555 dTLB-load-misses # 86.40% of all dTLB cache accesses ( +- 0.12% ) (39.03%)
765 iTLB-loads # 109.476 /sec ( +- 21.81% ) (39.44%)
4,370,351 iTLB-load-misses # 214320.09% of all iTLB cache accesses ( +- 1.44% ) (39.86%)
149,207,254 L1-dcache-prefetches # 21.352 M/sec ( +- 0.13% ) (40.27%)
7.25869 +- 0.00203 seconds time elapsed ( +- 0.03% )
After:
6,576.16 msec task-clock # 0.953 CPUs utilized ( +- 0.10% )
4,020 context-switches # 605.595 /sec ( +- 0.01% )
0 cpu-migrations # 0.000 /sec
2,052,056 page-faults # 309.133 K/sec ( +- 0.00% )
11,967,619,180 cycles # 1.803 GHz ( +- 0.36% ) (38.76%)
161,259,240 stalled-cycles-frontend # 1.38% frontend cycles idle ( +- 0.27% ) (36.58%)
253,605,302 stalled-cycles-backend # 2.16% backend cycles idle ( +- 4.45% ) (34.78%)
19,328,171,892 instructions # 1.65 insn per cycle
# 0.01 stalled cycles per insn ( +- 0.10% ) (31.46%)
5,213,967,902 branches # 785.461 M/sec ( +- 0.18% ) (30.68%)
12,385,170 branch-misses # 0.24% of all branches ( +- 0.26% ) (34.13%)
7,271,687,822 L1-dcache-loads # 1.095 G/sec ( +- 0.12% ) (35.29%)
649,873,045 L1-dcache-load-misses # 8.93% of all L1-dcache accesses ( +- 0.11% ) (41.41%)
1,950,037,608 L1-icache-loads # 293.764 M/sec ( +- 0.33% ) (43.11%)
31,365,566 L1-icache-load-misses # 1.62% of all L1-icache accesses ( +- 0.39% ) (45.89%)
6,767,809 dTLB-loads # 1.020 M/sec ( +- 0.47% ) (48.42%)
6,339,590 dTLB-load-misses # 95.43% of all dTLB cache accesses ( +- 0.50% ) (46.60%)
736 iTLB-loads # 110.875 /sec ( +- 1.79% ) (48.60%)
4,314,836 iTLB-load-misses # 518653.73% of all iTLB cache accesses ( +- 0.63% ) (42.91%)
144,950,156 L1-dcache-prefetches # 21.836 M/sec ( +- 0.37% ) (41.39%)
6.89935 +- 0.00703 seconds time elapsed ( +- 0.10% )
The performance is clearly better. There is no significant hotspot
improvement according to perf report, as there are quite a few
callers of memcg_swap_enabled and do_memsw_account (which calls
memcg_swap_enabled). Many pieces of minor optimizations resulted
in lower overhead for the branch predictor, and bettter performance.
Link: https://lkml.kernel.org/r/20220919180634.45958-3-ryncsn@gmail.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Muchun Song <songmuchun@bytedance.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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|---|---|---|
| .. | ||
| damon | ||
| kasan | ||
| kfence | ||
| kmsan | ||
| backing-dev.c | ||
| balloon_compaction.c | ||
| bootmem_info.c | ||
| cma_debug.c | ||
| cma_sysfs.c | ||
| cma.c | ||
| cma.h | ||
| compaction.c | ||
| debug_page_ref.c | ||
| debug_vm_pgtable.c | ||
| debug.c | ||
| dmapool.c | ||
| early_ioremap.c | ||
| fadvise.c | ||
| failslab.c | ||
| filemap.c | ||
| folio-compat.c | ||
| frontswap.c | ||
| gup_test.c | ||
| gup_test.h | ||
| gup.c | ||
| highmem.c | ||
| hmm.c | ||
| huge_memory.c | ||
| hugetlb_cgroup.c | ||
| hugetlb_vmemmap.c | ||
| hugetlb_vmemmap.h | ||
| hugetlb.c | ||
| hwpoison-inject.c | ||
| init-mm.c | ||
| internal.h | ||
| interval_tree.c | ||
| io-mapping.c | ||
| ioremap.c | ||
| Kconfig | ||
| Kconfig.debug | ||
| khugepaged.c | ||
| kmemleak.c | ||
| ksm.c | ||
| list_lru.c | ||
| maccess.c | ||
| madvise.c | ||
| Makefile | ||
| mapping_dirty_helpers.c | ||
| memblock.c | ||
| memcontrol.c | ||
| memfd.c | ||
| memory_hotplug.c | ||
| memory-failure.c | ||
| memory-tiers.c | ||
| memory.c | ||
| mempolicy.c | ||
| mempool.c | ||
| memremap.c | ||
| memtest.c | ||
| migrate_device.c | ||
| migrate.c | ||
| mincore.c | ||
| mlock.c | ||
| mm_init.c | ||
| mm_slot.h | ||
| mmap_lock.c | ||
| mmap.c | ||
| mmu_gather.c | ||
| mmu_notifier.c | ||
| mmzone.c | ||
| mprotect.c | ||
| mremap.c | ||
| msync.c | ||
| nommu.c | ||
| oom_kill.c | ||
| page_alloc.c | ||
| page_counter.c | ||
| page_ext.c | ||
| page_idle.c | ||
| page_io.c | ||
| page_isolation.c | ||
| page_owner.c | ||
| page_poison.c | ||
| page_reporting.c | ||
| page_reporting.h | ||
| page_table_check.c | ||
| page_vma_mapped.c | ||
| page-writeback.c | ||
| pagewalk.c | ||
| percpu-internal.h | ||
| percpu-km.c | ||
| percpu-stats.c | ||
| percpu-vm.c | ||
| percpu.c | ||
| pgalloc-track.h | ||
| pgtable-generic.c | ||
| process_vm_access.c | ||
| ptdump.c | ||
| readahead.c | ||
| rmap.c | ||
| rodata_test.c | ||
| secretmem.c | ||
| shmem.c | ||
| shrinker_debug.c | ||
| shuffle.c | ||
| shuffle.h | ||
| slab_common.c | ||
| slab.c | ||
| slab.h | ||
| slob.c | ||
| slub.c | ||
| sparse-vmemmap.c | ||
| sparse.c | ||
| swap_cgroup.c | ||
| swap_slots.c | ||
| swap_state.c | ||
| swap.c | ||
| swap.h | ||
| swapfile.c | ||
| truncate.c | ||
| usercopy.c | ||
| userfaultfd.c | ||
| util.c | ||
| vmalloc.c | ||
| vmpressure.c | ||
| vmscan.c | ||
| vmstat.c | ||
| workingset.c | ||
| z3fold.c | ||
| zbud.c | ||
| zpool.c | ||
| zsmalloc.c | ||
| zswap.c | ||