(switched to email. Please respond via emailed reply-to-all, not via the bugzilla web interface). On Fri, 25 Jan 2013 17:56:25 +0000 (UTC) bugzilla-daemon@xxxxxxxxxxxxxxxxxxx wrote: > https://bugzilla.kernel.org/show_bug.cgi?id=53031 > > Summary: kswapd in uninterruptible sleep state > Product: Memory Management > Version: 2.5 > Kernel Version: 3.7.3,3.7.4 > Platform: All > OS/Version: Linux > Tree: Mainline > Status: NEW > Severity: normal > Priority: P1 > Component: Other > AssignedTo: akpm@xxxxxxxxxxxxxxxxxxxx > ReportedBy: dairinin@xxxxxxxxx > Regression: No I'd say "Regression: yes"! Can you please run sysrq-W (or "echo w > /proc/sysrq-trigger" when kswapd is stuck so we can see where it is stuck? Also sysrq-m when it is in that state would be useful, thanks. [remainder retained for linux-mm to enjoy] > > Created an attachment (id=91781) > --> (https://bugzilla.kernel.org/attachment.cgi?id=91781) > Script do show what has changed in /proc/vmstat > > I have recently upgraded from 3.2 to 3.7.3, and I am seeing, that the > behavior of kswapd is strange at least. > > The machine is core2duo e7200 with 4G RAM, running 3.7.3 kernel. It has > compaction and THP (always) enabled. > > The machine is serving files over the network, so it is constantly under > memory pressure from page cache. The network is not very fast, and average disk > read rate is between 2 and 8 megabytes per second. > > In normal state, when page cache is filled, the free memory (according > to free and vmstat) is fluctuating between 100 and 150 megabytes, with > kswapd stepping in at 100M, quickly freeing to 150M and going to sleep > again. > > 1) On 3.7.3, after several hours after page cache is filled, kswapd enters > permanent D-state, with free memory keeping around 150M (high watermark, > I presume?). I have captured diffs for /proc/vmstat: > > $ ./diffshow 5 > ----8<---- > nr_free_pages:____________________________________38327 -> 38467 (140) > nr_active_anon:__________________________________110014 -> 110056 (42) > nr_inactive_file:______________________________526153 -> 526297 (144) > nr_active_file:__________________________________98802 -> 98864 (62) > nr_anon_pages:____________________________________103475 -> 103512 (37) > nr_file_pages:____________________________________627957 -> 628160 (203) > nr_dirty:______________________________________________15 -> 17 (2) > nr_page_table_pages:________________________2142 -> 2146 (4) > nr_kernel_stack:________________________________251 -> 253 (2) > nr_dirtied:__________________________________________1169312 -> 1169317 (5) > nr_written:__________________________________________1211979 -> 1211982 (3) > nr_dirty_threshold:__________________________159540 -> 159617 (77) > nr_dirty_background_threshold:____79770 -> 79808 (38) > pgpgin:__________________________________________________564650577 -> 564673241 (22664) > pgpgout:________________________________________________5117612 -> 5117668 (56) > pgalloc_dma32:____________________________________105487556 -> 105491067 (3511) > pgalloc_normal:__________________________________84026173 -> 84029309 (3136) > pgfree:__________________________________________________190134573 -> 190141394 (6821) > pgactivate:__________________________________________2750244 -> 2750283 (39) > pgfault:________________________________________________67214984 -> 67216222 (1238) > pgsteal_kswapd_dma32:______________________45793109 -> 45795077 (1968) > pgsteal_kswapd_normal:____________________61391466 -> 61394464 (2998) > pgscan_kswapd_dma32:________________________45812628 -> 45814596 (1968) > pgscan_kswapd_normal:______________________61465283 -> 61468281 (2998) > slabs_scanned:____________________________________30783104 -> 30786432 (3328) > pageoutrun:__________________________________________2936967 -> 2937033 (66) > > vmstat: > procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu---- > __r__ b____ swpd____ free____ buff__ cache____ si____ so______ bi______ bo____ in____ cs us sy id wa > __1__ 1 296924 153064____ 6936 2479664______ 0______ 0__ 5408________ 0 11711 1350__ 1__ 2 44 53 > __0__ 1 296924 152448____ 6928 2480048______ 0______ 0__ 6760________ 0 9723 1127__ 1__ 4 47 48 > __0__ 1 296924 152948____ 6916 2479464______ 0______ 0__ 3512______ 16 10392 1231__ 1__ 2 48 49 > __0__ 1 296924 153616____ 6916 2478804______ 0______ 0__ 2724________ 0 10279 1078__ 0__ 2 48 49 > __0__ 1 296924 152972____ 6916 2480132______ 0______ 0__ 3584________ 0 11289 1252__ 1__ 3 49 48 > __0__ 1 296924 155348____ 6916 2478396______ 0______ 0__ 6472________ 0 11285 1132__ 1__ 2 45 53 > __0__ 1 296924 152988____ 6916 2481024______ 0______ 0__ 5112______ 20 10039 1257__ 0__ 2 46 52 > __0__ 1 296924 152968____ 6916 2481016______ 0______ 0__ 3244________ 0 9586 1127__ 1__ 3 46 51 > __0__ 1 296924 153500____ 6916 2481196______ 0______ 0__ 3516________ 0 10899 1127__ 1__ 1 48 49 > __0__ 1 296924 152860____ 6916 2481688______ 0______ 0__ 4240________ 0 10418 1245__ 1__ 3 47 49 > __0__ 2 296924 153016____ 6912 2478584______ 0______ 0__ 5632________ 0 12136 1516__ 2__ 3 46 49 > __0__ 2 296924 153292____ 6912 2480984______ 0______ 0__ 4668________ 0 10872 1248__ 1__ 2 49 48 > __0__ 1 296924 152420____ 6916 2481844______ 0______ 0__ 4764______ 56 11236 1402__ 1__ 3 45 51 > __0__ 1 296924 152652____ 6916 2481204______ 0______ 0__ 4628________ 0 9422 1208__ 0__ 3 46 51 > > buddyinfo: > $ cat /proc/buddyinfo; sleep 1; cat /proc/buddyinfo > Node 0, zone__________ DMA__________ 0__________ 0__________ 0__________ 1__________ 2__________ 1__________ 1__________ 0____ > ____ 1__________ 1__________ 3 > Node 0, zone______ DMA32______ 515______ 205______ 242______ 201____ 1384______ 116________ 21__________ 8____ > ____ 1__________ 0__________ 0 > Node 0, zone____ Normal____ 1779__________ 0__________ 0________ 18________ 11__________ 3__________ 1__________ 3____ > ____ 0__________ 0__________ 0 > Node 0, zone__________ DMA__________ 0__________ 0__________ 0__________ 1__________ 2__________ 1__________ 1__________ 0____ > ____ 1__________ 1__________ 3 > Node 0, zone______ DMA32______ 480______ 197______ 227______ 176____ 1384______ 116________ 21__________ 8____ > ____ 1__________ 0__________ 0 > Node 0, zone____ Normal____ 1792__________ 9__________ 0________ 18________ 11__________ 3__________ 1__________ 3____ > ____ 0__________ 0__________ 0 > > 2) Also from time to time situation switches, where free memory is fixed at > some random point, fluctuating around this values at +-1 megabyte. > There is vmstat: > procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu---- > __r__ b____ swpd____ free____ buff__ cache____ si____ so______ bi______ bo____ in____ cs us sy id wa > __0__ 0 296480 381052____ 9732 2481324______ 1______ 2__ 2022______ 19____ 45____ 44__ 1__ 2 81 16 > __0__ 0 296480 382040____ 9732 2481180______ 0______ 0__ 2324________ 0 6505__ 825__ 1__ 2 96__ 1 > __0__ 0 296480 382500____ 9732 2481060______ 0______ 0__ 3824________ 0 5941 1046__ 1__ 2 96__ 1 > __0__ 0 296480 382092____ 9740 2480976______ 0______ 0__ 2048______ 16 7701__ 862__ 0__ 2 97__ 1 > __0__ 0 296480 382160____ 9740 2481896______ 0______ 0__ 5008________ 0 6443 1017__ 1__ 2 93__ 5 > __0__ 0 296480 382484____ 9740 2481668______ 0______ 0__ 2764________ 0 6972__ 799__ 0__ 2 97__ 1 > __0__ 0 296480 381912____ 9740 2481620______ 0______ 0__ 3780________ 0 7632 1036__ 1__ 2 96__ 1 > __0__ 0 296480 382240____ 9744 2481632______ 0______ 0__ 2796________ 0 7533__ 981__ 1__ 2 95__ 3 > __1__ 0 296480 382372____ 9748 2481756______ 0______ 0__ 2940________ 0 6565 1048__ 2__ 2 95__ 2 > __0__ 0 296480 383064____ 9748 2480320______ 0______ 0__ 5980________ 0 6352__ 979__ 0__ 3 92__ 5 > __0__ 0 296480 381380____ 9748 2481752______ 0______ 0__ 2732________ 0 6322__ 999__ 1__ 2 96__ 1 > __0__ 0 296480 381640____ 9748 2481992______ 0______ 0__ 2468________ 0 5640__ 849__ 0__ 2 97__ 2 > __0__ 0 296480 381684____ 9748 2481856______ 0______ 0__ 2760________ 0 7064__ 944__ 2__ 2 95__ 1 > __0__ 0 296480 381908____ 9748 2481664______ 0______ 0__ 2608________ 0 6797__ 952__ 0__ 2 94__ 4 > __0__ 0 296480 384024____ 9748 2479424______ 0______ 0__ 4804________ 0 6342 2767__ 1__ 2 94__ 4 > __0__ 0 296480 381948____ 9748 2481080______ 0______ 0__ 1868________ 0 6428__ 803__ 0__ 2 97__ 2 > __0__ 0 296480 382088____ 9748 2481524______ 0______ 0__ 3252________ 0 6464__ 990__ 1__ 1 98__ 1 > __0__ 0 296480 381884____ 9748 2481816______ 0______ 0__ 2892________ 0 7880__ 858__ 1__ 2 94__ 3 > __0__ 0 296480 382120____ 9748 2481848______ 0______ 0__ 2500________ 0 6207__ 905__ 1__ 1 96__ 2 > __0__ 1 296480 381976____ 9748 2479876______ 0______ 0__ 5188________ 0 6691__ 908__ 1__ 2 94__ 4 > __0__ 0 296480 381708____ 9748 2481584______ 0______ 0__ 2692________ 0 7904 1030__ 1__ 2 94__ 3 > __0__ 0 296480 382196____ 9748 2481704______ 0______ 0__ 2092________ 0 6715__ 722__ 1__ 1 97__ 1 > > > The /proc/vmstat diff is like this: > > $ ./diffshow 5 > ----8<---- > nr_free_pages:____________________________________94999 -> 95630 (631) > nr_inactive_anon:______________________________47076 -> 47196 (120) > nr_inactive_file:______________________________347048 -> 347080 (32) > nr_active_file:__________________________________270128 -> 270462 (334) > nr_file_pages:____________________________________619886 -> 620314 (428) > nr_dirty:______________________________________________10 -> 109 (99) > nr_kernel_stack:________________________________248 -> 249 (1) > nr_isolated_file:______________________________0 -> 10 (10) > nr_dirtied:__________________________________________1147486 -> 1147659 (173) > nr_written:__________________________________________1189947 -> 1190013 (66) > nr_dirty_threshold:__________________________168770 -> 168974 (204) > nr_dirty_background_threshold:____84385 -> 84487 (102) > pgpgin:__________________________________________________528729753 -> 528750521 (20768) > pgpgout:________________________________________________5013688 -> 5014216 (528) > pswpin:__________________________________________________77715 -> 77827 (112) > pgalloc_dma32:____________________________________95912002 -> 95912631 (629) > pgalloc_normal:__________________________________82241808 -> 82247860 (6052) > pgfree:__________________________________________________178827810 -> 178834939 (7129) > pgactivate:__________________________________________2644761 -> 2645104 (343) > pgfault:________________________________________________63365808 -> 63369261 (3453) > pgmajfault:__________________________________________23571 -> 23591 (20) > pgsteal_kswapd_normal:____________________60067802 -> 60072006 (4204) > pgscan_kswapd_normal:______________________60141548 -> 60145753 (4205) > slabs_scanned:____________________________________28914432 -> 28915456 (1024) > kswapd_low_wmark_hit_quickly:______589343 -> 589376 (33) > kswapd_high_wmark_hit_quickly:____763703 -> 763752 (49) > pageoutrun:__________________________________________2852120 -> 2852305 (185) > compact_blocks_moved:______________________10852682 -> 10852847 (165) > compact_pagemigrate_failed:__________39862700 -> 39865324 (2624) > > kswapd is stuck on normal zone! > > Also there is raw vmstat: > nr_free_pages 95343 > nr_inactive_anon 47196 > nr_active_anon 114110 > nr_inactive_file 348142 > nr_active_file 272638 > nr_unevictable 552 > nr_mlock 552 > nr_anon_pages 100386 > nr_mapped 6158 > nr_file_pages 623530 > nr_dirty 0 > nr_writeback 0 > nr_slab_reclaimable 21356 > nr_slab_unreclaimable 15570 > nr_page_table_pages 2045 > nr_kernel_stack 244 > nr_unstable 0 > nr_bounce 0 > nr_vmscan_write 149405 > nr_vmscan_immediate_reclaim 13896 > nr_writeback_temp 0 > nr_isolated_anon 0 > nr_isolated_file 4 > nr_shmem 48 > nr_dirtied 1147666 > nr_written 1190129 > nr_anon_transparent_hugepages 116 > nr_free_cma 0 > nr_dirty_threshold 169553 > nr_dirty_background_threshold 84776 > pgpgin 529292001 > pgpgout 5014788 > pswpin 77827 > pswpout 148890 > pgalloc_dma 0 > pgalloc_dma32 95940824 > pgalloc_normal 82395157 > pgalloc_movable 0 > pgfree 179010711 > pgactivate 2647284 > pgdeactivate 2513412 > pgfault 63427189 > pgmajfault 23606 > pgrefill_dma 0 > pgrefill_dma32 1915983 > pgrefill_normal 430939 > pgrefill_movable 0 > pgsteal_kswapd_dma 0 > pgsteal_kswapd_dma32 39927548 > pgsteal_kswapd_normal 60180622 > pgsteal_kswapd_movable 0 > pgsteal_direct_dma 0 > pgsteal_direct_dma32 14062458 > pgsteal_direct_normal 1894412 > pgsteal_direct_movable 0 > pgscan_kswapd_dma 0 > pgscan_kswapd_dma32 39946808 > pgscan_kswapd_normal 60254407 > pgscan_kswapd_movable 0 > pgscan_direct_dma 0 > pgscan_direct_dma32 14260652 > pgscan_direct_normal 1895350 > pgscan_direct_movable 0 > pgscan_direct_throttle 0 > pginodesteal 25301 > slabs_scanned 28931968 > kswapd_inodesteal 26119 > kswapd_low_wmark_hit_quickly 591050 > kswapd_high_wmark_hit_quickly 766006 > kswapd_skip_congestion_wait 15 > pageoutrun 2858733 > allocstall 156938 > pgrotated 161518 > compact_blocks_moved 10860505 > compact_pages_moved 411760 > compact_pagemigrate_failed 39987369 > compact_stall 29399 > compact_fail 23718 > compact_success 5681 > htlb_buddy_alloc_success 0 > htlb_buddy_alloc_fail 0 > unevictable_pgs_culled 6416 > unevictable_pgs_scanned 0 > unevictable_pgs_rescued 5337 > unevictable_pgs_mlocked 6672 > unevictable_pgs_munlocked 6120 > unevictable_pgs_cleared 0 > unevictable_pgs_stranded 0 > thp_fault_alloc 41 > thp_fault_fallback 302 > thp_collapse_alloc 507 > thp_collapse_alloc_failed 3704 > thp_split 111 > > Buddyinfo: > $ cat /proc/buddyinfo; sleep 1; cat /proc/buddyinfo > Node 0, zone__________ DMA__________ 0__________ 0__________ 0__________ 1__________ 2__________ 1__________ 1__________ 0____ > ____ 1__________ 1__________ 3 > Node 0, zone______ DMA32__ 29527__ 26916______ 489______ 221________ 40__________ 5__________ 0__________ 0____ > ____ 0__________ 0__________ 0 > Node 0, zone____ Normal____ 3158__________ 0__________ 0__________ 2__________ 1__________ 1__________ 1__________ 1____ > ____ 0__________ 0__________ 0 > Node 0, zone__________ DMA__________ 0__________ 0__________ 0__________ 1__________ 2__________ 1__________ 1__________ 0____ > ____ 1__________ 1__________ 3 > Node 0, zone______ DMA32__ 29527__ 26909______ 489______ 211________ 41__________ 5__________ 0__________ 0____ > ____ 0__________ 0__________ 0 > Node 0, zone____ Normal____ 2790________ 29__________ 0__________ 8__________ 1__________ 1__________ 1__________ 1____ > ____ 0__________ 0__________ 0 > > Zoneinfo: > $ cat /proc/zoneinfo > Node 0, zone__________ DMA > __ pages free________ 3976 > ______________ min__________ 64 > ______________ low__________ 80 > ______________ high________ 96 > ______________ scanned__ 0 > ______________ spanned__ 4080 > ______________ present__ 3912 > ______ nr_free_pages 3976 > ______ nr_inactive_anon 0 > ______ nr_active_anon 0 > ______ nr_inactive_file 0 > ______ nr_active_file 0 > ______ nr_unevictable 0 > ______ nr_mlock________ 0 > ______ nr_anon_pages 0 > ______ nr_mapped______ 0 > ______ nr_file_pages 0 > ______ nr_dirty________ 0 > ______ nr_writeback 0 > ______ nr_slab_reclaimable 0 > ______ nr_slab_unreclaimable 0 > ______ nr_page_table_pages 0 > ______ nr_kernel_stack 0 > ______ nr_unstable__ 0 > ______ nr_bounce______ 0 > ______ nr_vmscan_write 0 > ______ nr_vmscan_immediate_reclaim 0 > ______ nr_writeback_temp 0 > ______ nr_isolated_anon 0 > ______ nr_isolated_file 0 > ______ nr_shmem________ 0 > ______ nr_dirtied____ 0 > ______ nr_written____ 0 > ______ nr_anon_transparent_hugepages 0 > ______ nr_free_cma__ 0 > ______________ protection: (0, 3503, 4007, 4007) > __ pagesets > ______ cpu: 0 > __________________________ count: 0 > __________________________ high:__ 0 > __________________________ batch: 1 > __ vm stats threshold: 8 > ______ cpu: 1 > __________________________ count: 0 > __________________________ high:__ 0 > __________________________ batch: 1 > __ vm stats threshold: 8 > __ all_unreclaimable: 1 > __ start_pfn:________________ 16 > __ inactive_ratio:______ 1 > Node 0, zone______ DMA32 > __ pages free________ 87395 > ______________ min__________ 14715 > ______________ low__________ 18393 > ______________ high________ 22072 > ______________ scanned__ 0 > ______________ spanned__ 1044480 > ______________ present__ 896960 > ______ nr_free_pages 87395 > ______ nr_inactive_anon 18907 > ______ nr_active_anon 92242 > ______ nr_inactive_file 325044 > ______ nr_active_file 267577 > ______ nr_unevictable 0 > ______ nr_mlock________ 0 > ______ nr_anon_pages 51703 > ______ nr_mapped______ 4369 > ______ nr_file_pages 593009 > ______ nr_dirty________ 17 > ______ nr_writeback 0 > ______ nr_slab_reclaimable 14988 > ______ nr_slab_unreclaimable 11515 > ______ nr_page_table_pages 1305 > ______ nr_kernel_stack 133 > ______ nr_unstable__ 0 > ______ nr_bounce______ 0 > ______ nr_vmscan_write 140220 > ______ nr_vmscan_immediate_reclaim 62 > ______ nr_writeback_temp 0 > ______ nr_isolated_anon 0 > ______ nr_isolated_file 0 > ______ nr_shmem________ 10 > ______ nr_dirtied____ 810741 > ______ nr_written____ 862763 > ______ nr_anon_transparent_hugepages 116 > ______ nr_free_cma__ 0 > ______________ protection: (0, 0, 504, 504) > __ pagesets > ______ cpu: 0 > __________________________ count: 123 > __________________________ high:__ 186 > __________________________ batch: 31 > __ vm stats threshold: 24 > ______ cpu: 1 > __________________________ count: 29 > __________________________ high:__ 186 > __________________________ batch: 31 > __ vm stats threshold: 24 > __ all_unreclaimable: 0 > __ start_pfn:________________ 4096 > __ inactive_ratio:______ 5 > Node 0, zone____ Normal > __ pages free________ 3200 > ______________ min__________ 2116 > ______________ low__________ 2645 > ______________ high________ 3174 > ______________ scanned__ 0 > ______________ spanned__ 131072 > ______________ present__ 129024 > ______ nr_free_pages 3200 > ______ nr_inactive_anon 25943 > ______ nr_active_anon 24590 > ______ nr_inactive_file 23132 > ______ nr_active_file 10275 > ______ nr_unevictable 552 > ______ nr_mlock________ 552 > ______ nr_anon_pages 49050 > ______ nr_mapped______ 2088 > ______ nr_file_pages 35785 > ______ nr_dirty________ 3 > ______ nr_writeback 0 > ______ nr_slab_reclaimable 2340 > ______ nr_slab_unreclaimable 3926 > ______ nr_page_table_pages 786 > ______ nr_kernel_stack 114 > ______ nr_unstable__ 0 > ______ nr_bounce______ 0 > ______ nr_vmscan_write 9297 > ______ nr_vmscan_immediate_reclaim 13835 > ______ nr_writeback_temp 0 > ______ nr_isolated_anon 0 > ______ nr_isolated_file 10 > ______ nr_shmem________ 38 > ______ nr_dirtied____ 338110 > ______ nr_written____ 328638 > ______ nr_anon_transparent_hugepages 0 > ______ nr_free_cma__ 0 > ______________ protection: (0, 0, 0, 0) > __ pagesets > ______ cpu: 0 > __________________________ count: 152 > __________________________ high:__ 186 > __________________________ batch: 31 > __ vm stats threshold: 12 > ______ cpu: 1 > __________________________ count: 172 > __________________________ high:__ 186 > __________________________ batch: 31 > __ vm stats threshold: 12 > __ all_unreclaimable: 0 > __ start_pfn:________________ 1048576 > __ inactive_ratio:______ 1 > > I have tried disabling compaction (1000 > > /proc/sys/vm/extdefrag_threshold), and symptoms do change. There is no > kswapd stuck in D, but instead page cache is almost cleaned from time to > time > > Also I have a piece of code, which can reproduce the first problem with > kswapd in D state on another amd64 system, which has normal zone > artificially limited to the same ratio against dma32 zone. It needs a > large file, which is at least twice as large as system RAM (the larger > the better): > dd if=/dev/zero of=tf bs=1M count=$((1024*8)) > > Then start smth like this: > ./a.out tf 32 > and let it run for some time to fill the page cache. > > The code will random read the file in fixed chunks at fixed rate in two > "streams": one stream of 1/3 rate will be scattered across the whole > file and mark pages with WILLNEED. Another stream at 2/3 rate is > contained in 1/10 of a file and will not pass any hints. > > 3) Now I am running 3.7.4, and atm I see the second problem again, i.e. kswapd > is stuck on zone normal. > > -- > Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email > ------- You are receiving this mail because: ------- > You are the assignee for the bug. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>