From: Dave Chinner <david@fromorbit.com>
To: xfs@oss.sgi.com
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH 0/2] xfs: fix inode count underrun
Date: Wed, 6 May 2015 08:01:37 +1000 [thread overview]
Message-ID: <1430863299-9341-1-git-send-email-david@fromorbit.com> (raw)
Hi folks,
With the conversion of XFS to use the generic per-cpu superblocks, I
overlooked the fact that the update batch size is important to the
accuracy of the comparison function. Using different batch sizes
means percpu_counter_compare() doesn't detect when it should fall
back to percpu_counter_sum() for accuracy correctly, resulting in
counter comparisons being inaccurate. This leads to problems with
zero threshold detection in XFS.
To fix, add __percpu_counter_compare() to take a caller supplied
batch size. This fixes the XFS regression introduced in 4.1-rc1.
-Dave.
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WARNING: multiple messages have this Message-ID (diff)
From: Dave Chinner <david@fromorbit.com>
To: xfs@oss.sgi.com
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH 0/2] xfs: fix inode count underrun
Date: Wed, 6 May 2015 08:01:37 +1000 [thread overview]
Message-ID: <1430863299-9341-1-git-send-email-david@fromorbit.com> (raw)
Hi folks,
With the conversion of XFS to use the generic per-cpu superblocks, I
overlooked the fact that the update batch size is important to the
accuracy of the comparison function. Using different batch sizes
means percpu_counter_compare() doesn't detect when it should fall
back to percpu_counter_sum() for accuracy correctly, resulting in
counter comparisons being inaccurate. This leads to problems with
zero threshold detection in XFS.
To fix, add __percpu_counter_compare() to take a caller supplied
batch size. This fixes the XFS regression introduced in 4.1-rc1.
-Dave.
next reply other threads:[~2015-05-05 22:02 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-05 22:01 Dave Chinner [this message]
2015-05-05 22:01 ` [PATCH 0/2] xfs: fix inode count underrun Dave Chinner
2015-05-05 22:01 ` [PATCH 1/2] percpu_counter: batch size aware __percpu_counter_compare() Dave Chinner
2015-05-05 22:01 ` Dave Chinner
2015-05-06 4:36 ` Christoph Hellwig
2015-05-06 4:36 ` Christoph Hellwig
2015-05-06 4:46 ` Christoph Hellwig
2015-05-06 4:46 ` Christoph Hellwig
2015-05-06 5:43 ` Dave Chinner
2015-05-06 5:43 ` Dave Chinner
2015-05-06 5:53 ` Dave Chinner
2015-05-06 5:53 ` Dave Chinner
2015-05-06 6:11 ` Dave Chinner
2015-05-06 6:11 ` Dave Chinner
2015-05-05 22:01 ` [PATCH 2/2] xfs: inode counter needs to use __percpu_counter_compare Dave Chinner
2015-05-05 22:01 ` Dave Chinner
2015-05-06 4:38 ` Christoph Hellwig
2015-05-06 4:38 ` Christoph Hellwig
2015-05-06 5:45 ` Dave Chinner
2015-05-06 5:45 ` Dave Chinner
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