Re: [RESEND PATCH V2] mm: page_alloc: unreserve highatomic page blocks before oom

[Joakim Tjernlund]

On Tue, 2024-01-23 at 11:05 +0100, Michal Hocko wrote:
> On Mon 22-01-24 23:14:59, Joakim Tjernlund wrote:
> > On Mon, 2024-01-22 at 15:04 -0800, Greg KH wrote:
> [...]
> > > For mm patches like this, that are not explicitly tagged by the
> > > maintainers to be included in the stable tree, we need their ack to be
> > > able to apply them based on their requests.  So can you get that for
> > > this change and provide tested patches, we will be glad to queue them
> > > up.
> > 
> > I asked the author and he acknowledged it could be backported. Charan, please chim in.
> 
> The patch itself is safe to backport but it would be great to here what
> kind of problem you are trying to deal with. The issue fixed by this
> patch is more on a corner case side than something that many users
> should see. Could you share oom report you are seeing?

Yes, here it is:

Mar  9 12:52:39 xr kern.warn kernel: [ 1065.896824] xr-swm-install- invoked oom-killer: gfp_mask=0x1100cca(GFP_HIGHUSER_MOVABLE), order=0, oom_score_adj=0
Mar  9 12:52:40 xr kern.warn kernel: [ 1065.907321] CPU: 0 PID: 2428 Comm: xr-swm-install- Not tainted 5.15.129-xr-linux #1
Mar  9 12:52:40 xr kern.warn kernel: [ 1065.914974] Hardware name: infinera,xr (DT)
Mar  9 12:52:40 xr kern.warn kernel: [ 1065.919158] Call trace:
Mar  9 12:52:40 xr kern.warn kernel: [ 1065.921600]  dump_backtrace+0x0/0x148
Mar  9 12:52:40 xr kern.warn kernel: [ 1065.925310]  show_stack+0x14/0x1c
Mar  9 12:52:40 xr kern.warn kernel: [ 1065.928628]  dump_stack_lvl+0x64/0x7c
Mar  9 12:52:40 xr kern.warn kernel: [ 1065.932314]  dump_stack+0x14/0x2c
Mar  9 12:52:40 xr kern.warn kernel: [ 1065.935633]  dump_header+0x64/0x1fc
Mar  9 12:52:40 xr kern.warn kernel: [ 1065.939123]  oom_kill_process+0xc0/0x28c
Mar  9 12:52:40 xr kern.warn kernel: [ 1065.943063]  out_of_memory+0x2c8/0x2e0
Mar  9 12:52:40 xr kern.warn kernel: [ 1065.946811]  __alloc_pages_slowpath.constprop.0+0x4f4/0x5b0
Mar  9 12:52:40 xr kern.warn kernel: [ 1065.952388]  __alloc_pages+0xcc/0xdc
Mar  9 12:52:40 xr kern.warn kernel: [ 1065.955962]  __page_cache_alloc+0x18/0x20
Mar  9 12:52:40 xr kern.warn kernel: [ 1065.959993]  pagecache_get_page+0x14c/0x1bc
Mar  9 12:52:40 xr kern.warn kernel: [ 1065.964174]  filemap_fault+0x1f4/0x390
Mar  9 12:52:40 xr kern.warn kernel: [ 1065.967920]  __do_fault+0x48/0x78
Mar  9 12:52:40 xr kern.warn kernel: [ 1065.971253]  __handle_mm_fault+0x35c/0x7c0
Mar  9 12:52:40 xr kern.warn kernel: [ 1065.975351]  handle_mm_fault+0x2c/0xc4
Mar  9 12:52:40 xr kern.warn kernel: [ 1065.979101]  do_page_fault+0x224/0x350
Mar  9 12:52:40 xr kern.warn kernel: [ 1065.982857]  do_translation_fault+0x3c/0x58
Mar  9 12:52:40 xr kern.warn kernel: [ 1065.987038]  do_mem_abort+0x40/0xa4
Mar  9 12:52:40 xr kern.warn kernel: [ 1065.990526]  el0_ia+0x74/0xc8
Mar  9 12:52:40 xr kern.warn kernel: [ 1065.993498]  el0t_32_sync_handler+0xa8/0xe8
Mar  9 12:52:40 xr kern.warn kernel: [ 1065.997679]  el0t_32_sync+0x15c/0x160
Mar  9 12:52:40 xr kern.warn kernel: [ 1066.001379] Mem-Info:
Mar  9 12:52:40 xr kern.warn kernel: [ 1066.003665] active_anon:18 inactive_anon:2435 isolated_anon:0
Mar  9 12:52:40 xr kern.warn kernel: [ 1066.003665]  active_file:1 inactive_file:0 isolated_file:0
Mar  9 12:52:40 xr kern.warn kernel: [ 1066.003665]  unevictable:267 dirty:0 writeback:0
Mar  9 12:52:40 xr kern.warn kernel: [ 1066.003665]  slab_reclaimable:384 slab_unreclaimable:2223
Mar  9 12:52:40 xr kern.warn kernel: [ 1066.003665]  mapped:1 shmem:0 pagetables:309 bounce:0
Mar  9 12:52:41 xr kern.warn kernel: [ 1066.003665]  kernel_misc_reclaimable:0
Mar  9 12:52:41 xr kern.warn kernel: [ 1066.003665]  free:1054 free_pcp:24 free_cma:0
Mar  9 12:52:41 xr kern.warn kernel: [ 1066.037938] Node 0 active_anon:72kB inactive_anon:9740kB active_file:4kB inactive_file:0kB unevictable:1068kB isolated(anon):0kB isolated(file):0kB mapped:4kB dirty:0kB writeback:0kB shmem:0kB writeback_tmp:0kB kernel_stack:9
Mar  9 12:52:41 xr kern.warn kernel: [ 1066.061723] Normal free:4216kB min:128kB low:160kB high:192kB reserved_highatomic:4096KB active_anon:72kB inactive_anon:9740kB active_file:4kB inactive_file:0kB unevictable:1068kB writepending:0kB present:36864kB managed:2944
Mar  9 12:52:41 xr kern.warn kernel: [ 1066.087595] lowmem_reserve[]: 0 0
Mar  9 12:52:41 xr kern.warn kernel: [ 1066.090918] Normal: 206*4kB (MEH) 198*8kB (UMEH) 79*16kB (UMEH) 13*32kB (H) 2*64kB (H) 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 4216kB
Mar  9 12:52:41 xr kern.warn kernel: [ 1066.104104] 269 total pagecache pages
Mar  9 12:52:41 xr kern.warn kernel: [ 1066.107768] 9216 pages RAM
Mar  9 12:52:41 xr kern.warn kernel: [ 1066.110469] 0 pages HighMem/MovableOnly
Mar  9 12:52:41 xr kern.warn kernel: [ 1066.114305] 1855 pages reserved
Mar  9 12:52:41 xr kern.info kernel: [ 1066.117448] Tasks state (memory values in pages):
Mar  9 12:52:41 xr kern.info kernel: [ 1066.122150] [  pid  ]   uid  tgid total_vm      rss pgtables_bytes swapents oom_score_adj name
Mar  9 12:52:41 xr kern.info kernel: [ 1066.130764] [     77]     0    77      380       24    24576        0             0 mdev
Mar  9 12:52:41 xr kern.info kernel: [ 1066.138857] [    224]     0   224      364        9    24576        0             0 syslogd
Mar  9 12:52:41 xr kern.info kernel: [ 1066.147208] [    227]     0   227      364        9    28672        0             0 klogd
Mar  9 12:52:41 xr kern.info kernel: [ 1066.155385] [    242]     0   242      301       10    28672        0             0 dropbear
Mar  9 12:52:41 xr kern.info kernel: [ 1066.163824] [    248]     0   248      337       38    24576        0             0 dhcpcd
Mar  9 12:52:41 xr kern.info kernel: [ 1066.172090] [    259]     0   259      899       34    32768        0             0 watchdog
Mar  9 12:52:41 xr kern.info kernel: [ 1066.180528] [    261]     0   261      741       33    32768        0             0 rpmsg_broker
Mar  9 12:52:41 xr kern.info kernel: [ 1066.189311] [    263]     0   263    75466      965   622592        0             0 waactrl-main
Mar  9 12:52:41 xr kern.info kernel: [ 1066.198095] [    320]     0   320     1127       90    32768        0             0 xr-fm-agent
Mar  9 12:52:41 xr kern.info kernel: [ 1066.206794] [    324]     0   324      797       40    24576        0             0 factory_reset
Mar  9 12:52:41 xr kern.info kernel: [ 1066.215668] [    328]     0   328     1674      242    40960        0             0 xr-cm-agent
Mar  9 12:52:41 xr kern.info kernel: [ 1066.224628] [    331]     0   331      707       31    32768        0             0 mmcu-agent
Mar  9 12:52:41 xr kern.info kernel: [ 1066.233245] [    334]     0   334     4054      427    49152        0             0 xr-swm-agent
Mar  9 12:52:41 xr kern.info kernel: [ 1066.242031] [    338]     0   338     1129       94    32768        0             0 xr-pm-agent
Mar  9 12:52:41 xr kern.info kernel: [ 1066.250729] [    364]     0   364      734       34    32768        0             0 process_supervi
Mar  9 12:52:41 xr kern.info kernel: [ 1066.259774] [    399]     0   399     1327      215    32768        0             0 swupdate
Mar  9 12:52:41 xr kern.info kernel: [ 1066.268212] [    413]     0   413      370       13    28672        0             0 sh
Mar  9 12:52:41 xr kern.info kernel: [ 1066.276131] [   2072]     0  2072      306       13    28672        0             0 dropbear
Mar  9 12:52:42 xr kern.info kernel: [ 1066.284569] [   2081]     0  2081      366       11    24576        0             0 sh
Mar  9 12:52:42 xr kern.info kernel: [ 1066.292492] [   2427]     0  2427      876       93    28672        0             0 xr-swm-install-
Mar  9 12:52:42 xr kern.info kernel: [ 1066.301536] [   2468]     0  2468      546       25    28672        0             0 ip
Mar  9 12:52:42 xr kern.info kernel: [ 1066.309453] oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),task=waactrl-main,pid=263,uid=0
Mar  9 12:52:42 xr kern.err kernel: [ 1066.318197] Out of memory: Killed process 263 (waactrl-main) total-vm:301864kB, anon-rss:3860kB, file-rss:0kB, shmem-rss:0kB, UID:0 pgtables:608kB oom_score_adj:0