diff options
| author | Kent Overstreet <kent.overstreet@linux.dev> | 2024-01-23 00:01:07 -0500 |
|---|---|---|
| committer | Kent Overstreet <kent.overstreet@linux.dev> | 2024-03-13 21:22:24 -0400 |
| commit | 91dcad18d38849f1702e0d50f5598bb3614c8ff8 (patch) | |
| tree | 8684fd85fd37944babb2e386c6392afbc2ef34a2 /fs/bcachefs/opts.h | |
| parent | 835cd3e147a9a8f8acfe7f3a405c582f04e90a33 (diff) | |
bcachefs: Pin btree cache in ram for random access in fsck
Various phases of fsck involve checking references from one btree to
another: this means doing a sequential scan of one btree, and then
mostly random access into the second.
This is particularly painful for checking extents <-> backpointers; we
can prefetch btree node access on the sequential scan, but not on the
random access portion, and this is particularly painful on spinning
rust, where we'd like to keep the pipeline fairly full of btree node
reads so that the elevator can reduce seeking.
This patch implements prefetching and pinning of the portion of the
btree that we'll be doing random access to. We already calculate how
much of the random access btree will fit in memory so it's a fairly
straightforward change.
This will put more pressure on system memory usage, so we introduce a
new option, fsck_memory_usage_percent, which is the percentage of total
system ram that fsck is allowed to pin.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Diffstat (limited to 'fs/bcachefs/opts.h')
| -rw-r--r-- | fs/bcachefs/opts.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/bcachefs/opts.h b/fs/bcachefs/opts.h index 9a83aca31b4b..136083c11f3a 100644 --- a/fs/bcachefs/opts.h +++ b/fs/bcachefs/opts.h @@ -337,6 +337,11 @@ enum fsck_err_opts { OPT_BOOL(), \ BCH2_NO_SB_OPT, false, \ NULL, "Run fsck on mount") \ + x(fsck_memory_usage_percent, u8, \ + OPT_FS|OPT_MOUNT, \ + OPT_UINT(20, 70), \ + BCH2_NO_SB_OPT, 50, \ + NULL, "Maximum percentage of system ram fsck is allowed to pin")\ x(fix_errors, u8, \ OPT_FS|OPT_MOUNT, \ OPT_FN(bch2_opt_fix_errors), \ |