From: Christoph Hellwig <hch@lst.de>
To: linux-xfs@vger.kernel.org
Cc: peterz@infradead.org
Subject: remove the XFS iolock, V2
Date: Fri, 21 Oct 2016 18:50:04 +0200 [thread overview]
Message-ID: <1477068606-21936-1-git-send-email-hch@lst.de> (raw)
Hi all,
this series remove the per-inode iolock in XFS which has historically
been used to serialize I/O. But now that the VFS i_mutex has been
replaced with a rw_semaphore called i_rwsem there is no need to keep
the XFS lock - by relying on the VFS i_rwsem we unify the locking
constraints between difference file systems, reduce the XFS inode size
and reduce the amount of atomic instruction we do with every read
or write call.
Note that Dave asked to kill the XFS mrlock first the last time this
series was posted - while that seems desirable it's not easily possible
due to the way XFS may offload allocator work to a workqueues, and how
lockdep doesn't recognize that. As removing mrlocks entirely would
be just a cleanup without an affect on locking hierchies or inode
size reduction (except for debug builds) I would prefer to get this
series to remove the iolock in first, and then see what we can do about
the two remaining mrlocks later.
next reply other threads:[~2016-10-21 16:50 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-21 16:50 Christoph Hellwig [this message]
2016-10-21 16:50 ` [PATCH 1/2] locking/lockdep: Provide a type check for lock_is_held Christoph Hellwig
2016-10-21 16:50 ` [PATCH 2/2] xfs: remove i_iolock and use i_rwsem in the VFS inode instead Christoph Hellwig
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