diff options
| author | Josef Bacik <josef@toxicpanda.com> | 2020-10-09 09:28:27 -0400 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2021-02-08 22:58:59 +0100 |
| commit | 88a777a6e5272106bdc96b1032d89b0ddc0e526f (patch) | |
| tree | 717a835899027c6bf53cdf996adfa59244ca181a /fs/btrfs/space-info.h | |
| parent | 2e294c60497f29ab8791f4b99f348b22d70dd3c3 (diff) | |
btrfs: implement space clamping for preemptive flushing
Starting preemptive flushing at 50% of available free space is a good
start, but some workloads are particularly abusive and can quickly
overwhelm the preemptive flushing code and drive us into using tickets.
Handle this by clamping down on our threshold for starting and
continuing to run preemptive flushing. This is particularly important
for our overcommit case, as we can really drive the file system into
overages and then it's more difficult to pull it back as we start to
actually fill up the file system.
The clamping is essentially 2^CLAMP, but we start at 1 so whatever we
calculate for overcommit is the baseline.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/space-info.h')
| -rw-r--r-- | fs/btrfs/space-info.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/btrfs/space-info.h b/fs/btrfs/space-info.h index 74706f604bce..e237156ce888 100644 --- a/fs/btrfs/space-info.h +++ b/fs/btrfs/space-info.h @@ -22,6 +22,10 @@ struct btrfs_space_info { the space info if we had an ENOSPC in the allocator. */ + int clamp; /* Used to scale our threshold for preemptive + flushing. The value is >> clamp, so turns + out to be a 2^clamp divisor. */ + unsigned int full:1; /* indicates that we cannot allocate any more chunks for this space */ unsigned int chunk_alloc:1; /* set if we are allocating a chunk */ |