On 2021-07-29 15:20:57 [+0200], Vlastimil Babka wrote: > Changes since v2 [5]: With PARTIAL enabled on top of -rc3: | root@debpg:~# grep ^kmalloc-512 /proc/slabinfo | kmalloc-512 3552 3552 512 32 4 : tunables 0 0 0 : slabdata 111 111 0 | root@debpg:~# hackbench -g80 | Running in process mode with 80 groups using 40 file descriptors each (== 3200 tasks) | Each sender will pass 100 messages of 100 bytes | Time: 0.643 | root@debpg:~# grep ^kmalloc-512 /proc/slabinfo | kmalloc-512 954080 954080 512 32 4 : tunables 0 0 0 : slabdata 29815 29815 0 | root@debpg:~# hackbench -g80 | Running in process mode with 80 groups using 40 file descriptors each (== 3200 tasks) | Each sender will pass 100 messages of 100 bytes | Time: 0.604 | root@debpg:~# grep ^kmalloc-512 /proc/slabinfo | kmalloc-512 1647904 1647904 512 32 4 : tunables 0 0 0 : slabdata 51497 51497 0 | root@debpg:~# echo 1 > /sys/kernel/slab/kmalloc-512/shrink | root@debpg:~# grep ^kmalloc-512 /proc/slabinfo | kmalloc-512 640 1120 512 32 4 : tunables 0 0 0 : slabdata 35 35 0 otherwise a few more hackbench invocations without manual shirnk lead to OOM-killer: | oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=/,mems_allowed=0,task=systemd-logind,pid=1713,uid=0 | Out of memory: Killed process 1713 (systemd-logind) total-vm:15720kB, anon-rss:956kB, file-rss:0kB, shmem-rss:0kB, UID:0 pgtables:72kB oom_score_adj:0 | Mem-Info: | active_anon:56 inactive_anon:24782 isolated_anon:0 | active_file:13 inactive_file:45 isolated_file:0 | unevictable:0 dirty:0 writeback:0 | slab_reclaimable:8749 slab_unreclaimable:894017 | mapped:68 shmem:118 pagetables:28612 bounce:0 | free:8407 free_pcp:36 free_cma:0 | Node 0 active_anon:224kB inactive_anon:99128kB active_file:260kB inactive_file:712kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:764kB dirty:0kB writebaco | Node 0 DMA free:15360kB min:28kB low:40kB high:52kB reserved_highatomic:0KB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writependiB | lowmem_reserve[]: 0 1939 3915 3915 | Node 0 DMA32 free:11696kB min:3960kB low:5944kB high:7928kB reserved_highatomic:0KB active_anon:0kB inactive_anon:40740kB active_file:0kB inactive_file:4kB unevictable:0kB | lowmem_reserve[]: 0 0 1975 1975 | Node 0 Normal free:5692kB min:4032kB low:6052kB high:8072kB reserved_highatomic:0KB active_anon:224kB inactive_anon:58440kB active_file:440kB inactive_file:100kB unevictaB | lowmem_reserve[]: 0 0 0 0 | Node 0 DMA: 0*4kB 0*8kB 0*16kB 0*32kB 0*64kB 0*128kB 0*256kB 0*512kB 1*1024kB (U) 1*2048kB (M) 3*4096kB (M) = 15360kB | Node 0 DMA32: 11*4kB (UM) 15*8kB (M) 20*16kB (UME) 12*32kB (UME) 7*64kB (ME) 5*128kB (UME) 4*256kB (UM) 6*512kB (ME) 4*1024kB (M) 1*2048kB (M) 0*4096kB = 12196kB | Node 0 Normal: 324*4kB (UME) 221*8kB (UME) 60*16kB (UM) 24*32kB (UME) 5*64kB (UM) 2*128kB (U) 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 5368kB | Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB | 189 total pagecache pages | 0 pages in swap cache | Swap cache stats: add 0, delete 0, find 0/0 | Free swap = 0kB | Total swap = 0kB | 1048432 pages RAM | 0 pages HighMem/MovableOnly | 41108 pages reserved | Unreclaimable slab info: … | kmalloc-512 2144352KB 2144352KB This does not happen if I disable SLUB_CPU_PARTIAL. Sebastian
