ENOSPC delalloc flushing fixes
Get series with b4
b4 am [email protected]Versions newest first · linked by author and title
- v3 Latest9 patches 7 repliesIn review
- v28 patches 7 repliesSuperseded
- v16 patches 2 repliesSuperseded
Changes in v3 from the cover letter
- Reordered the patches to have "btrfs: wake up async_delalloc_pages waiters after submit" come first, as it's a general fix that we need.
- Fixed the nit that Nikolay pointed out in "btrfs: handle shrink_delalloc pages calculation differently".
- Added "btrfs: include delalloc related info in dump space info tracepoint" to include the delalloc_bytes and ordered_bytes in the dump_space_info tracepoint.
Patches in v3 No applies recorded yet
| # | Subject and files | Size | Replies | Applied |
|---|---|---|---|---|
| 1/9 | btrfs: wake up async_delalloc_pages waiters after submitfs/ | +5 | 0 replies | |
| 2/9 | btrfs: include delalloc related info in dump space info tracepointinclude/ | +10 | 0 replies | |
| 3/9 | btrfs: enable a tracepoint when we fail ticketsfs/ include/ | +8 | 0 replies | |
| 4/9 | btrfs: handle shrink_delalloc pages calculation differentlyfs/ fs/ include/ | +34 | 0 replies | |
| 5/9 | btrfs: wait on async extents when flushing delallocfs/ fs/ | +40 | 0 replies | |
| 6/9 | fs: add a filemap_fdatawrite_wbc helperinclude/ mm/ | +28 | 2 replies | |
| 7/9 | btrfs: use the filemap_fdatawrite_wbc helper for delalloc shrinkingfs/ | +1 | 0 replies | |
| 8/9 | 9p: migrate from sync_inode to filemap_fdatawrite_wbcfs/ | +1 | 2 replies | |
| 9/9 | fs: kill sync_inodefs/ include/ | +1 | 1 reply |
Reviews trailers per patch
5 of 9 patches have a Reviewed-by or Acked-by of their own; the series has one for all of them.
| Patch | Nikolay Borisov | Christoph Hellwig |
|---|---|---|
| Series | R-b | |
| 1/9 | R-b | |
| 2/9 | ||
| 3/9 | ||
| 4/9 | ||
| 5/9 | ||
| 6/9 | R-b | R-b |
| 7/9 | R-b | |
| 8/9 | R-b | |
| 9/9 | R-b |
Trailers given in replies are filled; those carried in the patches from earlier versions are outlined with dashes.
Cover letter [PATCH v3 0/9] ENOSPC delalloc flushing fixes
v2->v3:
- Reordered the patches to have "btrfs: wake up async_delalloc_pages waiters after submit" come first, as it's a general fix that we need.
- Fixed the nit that Nikolay pointed out in "btrfs: handle shrink_delalloc pages calculation differently".
- Added "btrfs: include delalloc related info in dump space info tracepoint" to include the delalloc_bytes and ordered_bytes in the dump_space_info tracepoint.
v1->v2:
- Two extra patches to remove the last user of sync_inode() (p9fs) and then remove sync_inode() itself, as per hch's request
--- Original email ---
Hello,
I've been debugging and fixing a problem we hit in production related to getting ENOSPC when we still should have had space to use. A variety of different things were going wrong, but one of them was sometimes we wouldn't wait for all of delalloc to be flushed. This series of patches fixes a few problems in this area, starting with
btrfs: handle shrink_delalloc pages calculation differently
When we switched to writing pages instead of full inodes for flushing we didn't adjust the counters to give us pages, instead using the "items" amount. This is incorrect as we'd just not flush that much delalloc, leaving a lot laying around when we finally ENOSPC'd.
The next bit are related to compression, as we have compression on everywhere in production.
btrfs: wait on async extents when flushing delalloc
btrfs: wake up async_delalloc_pages waiters after submit
I ripped this code out because I added a second sync_inode() if we had async extents in order to do the proper waiting. However sync_inode() could skip writeout if writeout had begun already on the inode, so we still need this waiting in order to make sure we don't try to wait on ordered extents until all ordered extents have been created.
And finally these two patches
fs: add a filemap_fdatawrite_wbc helper
btrfs: use the filemap_fdatawrite_wbc helper for delalloc shrinking
We need a writeback helper that will take a wbc and not try to do anything fancy other than write out the inode we want. sync_inode() has the drawback that it will skip writeout if the inode is currently under writeback, and thus we won't wait properly.
I ran this series through fsperf, the results ar eposted below. I'm still printing the %diff, but I'm also printing the stdev so you can see the variance in teh values we expect. Generally there is no change or it's within the normal range. These patches really only affect anything when we're very full on space.
I also ran this through the enospc stress test and saw no early enospc. Thanks,
Josef
dbench60 results
metric baseline current stdev diff
==============================================================
qpathinfo 11.26 11.87 0.64 5.35%
throughput 652.90 628.99 65.68 -3.66% flush 22292.41 35005.49 15197.94 57.03% qfileinfo 1.04 1.24 0.17 19.02% ntcreatex 3965.31 6167.38 7790.74 55.53% qfsinfo 1.79 1.41 0.40 -20.88% close 1.81 1.95 0.39 7.67% sfileinfo 4.96 5.50 1.13 10.70%
rename 2640.98 5844.86 5873.86 121.31%
find 12.29 12.83 1.00 4.36%
unlink 3310.42 4809.88 7179.77 45.30%
writex 12521.22 37992.79 7567.72 203.43%
deltree 409.86 363.46 224.63 -11.32%
readx 2.37 4.18 0.66 76.01% mkdir 0.03 0.11 0.01 271.06% lockx 0.44 0.17 0.27 -61.83% unlockx 0.16 0.64 0.11 291.70%
emptyfiles500k results
metric baseline current stdev diff
======================================================================
write_io_kbytes 125000 125000 0 0.00% read_clat_ns_p99 0 0 0 0.00% write_bw_bytes 1.83e+08 1.77e+08 5516543.33 -3.19% read_iops 0 0 0 0.00% write_clat_ns_p50 17536 17792 273.68 1.46% read_io_kbytes 0 0 0 0.00% read_io_bytes 0 0 0 0.00% write_clat_ns_p99 72576 74240 2677.97 2.29% read_bw_bytes 0 0 0 0.00% elapsed 1 1 0 0.00% write_lat_ns_min 0 0 0 0.00% sys_cpu 91.86 91.29 0.66 -0.63% write_lat_ns_max 0 0 0 0.00% read_lat_ns_min 0 0 0 0.00% write_iops 44583.10 43162.98 1346.81 -3.19% read_lat_ns_max 0 0 0 0.00% read_clat_ns_p50 0 0 0 0.00%
smallfiles100k results
metric baseline current stdev diff
========================================================================
write_io_kbytes 2.04e+08 2.04e+08 0 0.00% read_clat_ns_p99 0 0 0 0.00% write_bw_bytes 1.33e+08 1.40e+08 15033768.39 5.20% read_iops 0 0 0 0.00% write_clat_ns_p50 6424 6688 79.77 4.11% read_io_kbytes 0 0 0 0.00% read_io_bytes 0 0 0 0.00% write_clat_ns_p99 15960 16320 251.24 2.26% read_bw_bytes 0 0 0 0.00% elapsed 1592.50 1492 234.98 -6.31% write_lat_ns_min 2730.75 2768 45.73 1.36% sys_cpu 5.75 6.25 0.65 8.68% write_lat_ns_max 5.17e+08 1.52e+08 1.05e+09 -70.54% read_lat_ns_min 0 0 0 0.00% write_iops 32545.54 34239.34 3670.35 5.20% read_lat_ns_max 0 0 0 0.00% read_clat_ns_p50 0 0 0 0.00%
bufferedrandwrite16g results
metric baseline current stdev diff
===========================================================================
write_io_kbytes 16777216 16777216 0 0.00% read_clat_ns_p99 0 0 0 0.00% write_bw_bytes 91729211.62 94071836 13859731.84 2.55% read_iops 0 0 0 0.00% write_clat_ns_p50 12704 11840 1227.26 -6.80% read_io_kbytes 0 0 0 0.00% read_io_bytes 0 0 0 0.00% write_clat_ns_p99 31136 32384 2925.86 4.01% read_bw_bytes 0 0 0 0.00%
elapsed 191.38 183 25.98 -4.38%write_lat_ns_min 3961.25 4068 95.29 2.69%sys_cpu 31.83 29.77 6.85 -6.47%write_lat_ns_max 3.05e+10 1.70e+10 1.95e+10 -44.34%
read_lat_ns_min 0 0 0 0.00% write_iops 22394.83 22966.76 3383.72 2.55% read_lat_ns_max 0 0 0 0.00% read_clat_ns_p50 0 0 0 0.00%
dio4kbs16threads results
metric baseline current stdev diff
===========================================================================write_io_kbytes 4187092 4949612 599817.04 18.21%read_clat_ns_p99 0 0 0 0.00%write_bw_bytes 71448568.62 84467746 10233293.68 18.22%read_iops 0 0 0 0.00%write_clat_ns_p50 245504 240640 4370.25 -1.98%
read_io_kbytes 0 0 0 0.00% read_io_bytes 0 0 0 0.00% write_clat_ns_p99 22249472 20054016 1120427.41 -9.87% read_bw_bytes 0 0 0 0.00% elapsed 61 61 0 0.00% write_lat_ns_min 38440 38571 225.10 0.34%
sys_cpu 3.89 4.57 0.46 17.47%write_lat_ns_max 1.23e+09 9.48e+08 7.00e+08 -23.22%read_lat_ns_min 0 0 0 0.00%write_iops 17443.50 20622.01 2498.36 18.22%
read_lat_ns_max 0 0 0 0.00% read_clat_ns_p50 0 0 0 0.00%
randwrite2xram results
metric baseline current stdev diff
========================================================================
write_io_kbytes 33948247 34359528 4793805.63 1.21% read_clat_ns_p99 0 0 0 0.00% write_bw_bytes 1.15e+08 1.17e+08 17455355.14 1.47% read_iops 0 0 0 0.00% write_clat_ns_p50 15232 14400 1043.81 -5.46% read_io_kbytes 0 0 0 0.00% read_io_bytes 0 0 0 0.00% write_clat_ns_p99 95264 67072 25379.05 -29.59% read_bw_bytes 0 0 0 0.00% elapsed 313.62 314 5.10 0.12% write_lat_ns_min 5399.38 5658 126.19 4.79% sys_cpu 11.61 11.06 2.04 -4.69% write_lat_ns_max 3.16e+10 2.91e+10 1.46e+10 -8.05% read_lat_ns_min 0 0 0 0.00% write_iops 28099.86 28511.67 4261.56 1.47% read_lat_ns_max 0 0 0 0.00% read_clat_ns_p50 0 0 0 0.00%
untarfirefox results
metric baseline current stdev diff
======================================================
elapsed 46.89 46.75 0.18 -0.29%
Josef Bacik (9):
btrfs: wake up async_delalloc_pages waiters after submit
btrfs: include delalloc related info in dump space info tracepoint
btrfs: enable a tracepoint when we fail tickets
btrfs: handle shrink_delalloc pages calculation differently
btrfs: wait on async extents when flushing delalloc
fs: add a filemap_fdatawrite_wbc helper
btrfs: use the filemap_fdatawrite_wbc helper for delalloc shrinking 9p: migrate from sync_inode to filemap_fdatawrite_wbc
fs: kill sync_inode
fs/9p/vfs_file.c | 7 +-- fs/btrfs/ctree.h | 9 ++-- fs/btrfs/inode.c | 16 +++---- fs/btrfs/space-info.c | 82 ++++++++++++++++++++++++++++++------ fs/fs-writeback.c | 19 +-------- include/linux/fs.h | 3 +- include/trace/events/btrfs.h | 21 +++++++-- mm/filemap.c | 35 +++++++++++---- 8 files changed, 128 insertions(+), 64 deletions(-)
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