From: Dave Chinner <david@fromorbit.com>
To: xfs@oss.sgi.com
Subject: [RFC] [PATCH 0/4] Replace buffer cache hash with rbtrees
Date: Thu, 9 Sep 2010 01:12:54 +1000 [thread overview]
Message-ID: <1283958778-28610-1-git-send-email-david@fromorbit.com> (raw)
This patch series cleans up several unconventional buffer uses to
avoid using cached buffers, and then converts the buffer cache
indexing to use a set of per-ag rbtrees rather than a hash. This
version show no performance degradation on my 1.1TB filesystem under
parallel create and unlink compared to the existing enlarged hash
cache. In both cases _xfs_buf_find() is consuming 5-6% of the entire
CPU time of the workload.
This patchset is needed to prepare for moving away from using the
page cache as the backing cache and instead maintaining a LRU of
cached buffers. This is necessary because on larger filesystems
we are completely unable to maintain the working set of metadata
buffers hot in cache as we cannot control page cache reclaim. It
means that we need to be able to hold a lot more buffers in memory
than we currently do and as such the hash based indexing needs
replacing first.
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next reply other threads:[~2010-09-08 15:12 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-08 15:12 Dave Chinner [this message]
2010-09-08 15:12 ` [PATCH 1/4] xfs: kill XBF_FS_MANAGED buffers Dave Chinner
2010-09-09 1:33 ` Christoph Hellwig
2010-09-10 3:10 ` Dave Chinner
2010-09-10 21:17 ` Alex Elder
2010-09-08 15:12 ` [PATCH 2/4] xfs: use unhashed buffers for size checks Dave Chinner
2010-09-09 1:38 ` Christoph Hellwig
2010-09-10 3:14 ` Dave Chinner
2010-09-10 21:33 ` Alex Elder
2010-09-08 15:12 ` [PATCH 3/4] xfs: remove buftarg hash for external devices Dave Chinner
2010-09-09 1:39 ` Christoph Hellwig
2010-09-08 15:12 ` [PATCH 4/4] xfs: convert buffer cache hash to rbtree Dave Chinner
2010-09-09 1:51 ` Christoph Hellwig
2010-09-10 3:22 ` Dave Chinner
2010-09-13 16:59 ` Alex Elder
2010-09-13 16:53 ` Alex Elder
2010-09-14 7:13 ` Dave Chinner
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