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| author | Chris Mason <chris.mason@oracle.com> | 2008-07-31 15:42:53 -0400 |
|---|---|---|
| committer | Chris Mason <chris.mason@oracle.com> | 2008-09-25 11:04:05 -0400 |
| commit | 61b4944018449003ac5f9757f4d125dce519cf51 (patch) | |
| tree | 553855996c641a945344db870b6dfd0d2d02086e /fs/btrfs/async-thread.c | |
| parent | 37d1aeee3990385e9bb436c50c2f7e120a668df6 (diff) | |
| download | blackbird-op-linux-61b4944018449003ac5f9757f4d125dce519cf51.tar.gz blackbird-op-linux-61b4944018449003ac5f9757f4d125dce519cf51.zip | |
Btrfs: Fix streaming read performance with checksumming on
Large streaming reads make for large bios, which means each entry on the
list async work queues represents a large amount of data. IO
congestion throttling on the device was kicking in before the async
worker threads decided a single thread was busy and needed some help.
The end result was that a streaming read would result in a single CPU
running at 100% instead of balancing the work off to other CPUs.
This patch also changes the pre-IO checksum lookup done by reads to
work on a per-bio basis instead of a per-page. This results in many
extra btree lookups on large streaming reads. Doing the checksum lookup
right before bio submit allows us to reuse searches while processing
adjacent offsets.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/async-thread.c')
| -rw-r--r-- | fs/btrfs/async-thread.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/btrfs/async-thread.c b/fs/btrfs/async-thread.c index 5fe6a0d532ed..bc2980c433ef 100644 --- a/fs/btrfs/async-thread.c +++ b/fs/btrfs/async-thread.c @@ -160,7 +160,7 @@ void btrfs_init_workers(struct btrfs_workers *workers, int max) INIT_LIST_HEAD(&workers->idle_list); spin_lock_init(&workers->lock); workers->max_workers = max; - workers->idle_thresh = 64; + workers->idle_thresh = 32; } /* |
