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Date:   Fri, 22 Nov 2019 16:53:32 +1100
From:   Matthew Bobrowski <mbobrowski@mbobrowski.org>
To:     Ritesh Harjani <riteshh@linux.ibm.com>
Cc:     jack@suse.cz, tytso@mit.edu, linux-ext4@vger.kernel.org,
        linux-fsdevel@vger.kernel.org
Subject: Re: [RFCv3 1/4] ext4: fix ext4_dax_read/write inode locking sequence
 for IOCB_NOWAIT
Message-ID: <20191122055330.GA13688@bobrowski>
References: <20191120050024.11161-1-riteshh@linux.ibm.com>
 <20191120050024.11161-2-riteshh@linux.ibm.com>
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On Wed, Nov 20, 2019 at 10:30:21AM +0530, Ritesh Harjani wrote:
> Apparently our current rwsem code doesn't like doing the trylock, then
> lock for real scheme.  So change our dax read/write methods to just do the
> trylock for the RWF_NOWAIT case.
> This seems to fix AIM7 regression in some scalable filesystems upto ~25%
> in some cases. Claimed in commit 942491c9e6d6 ("xfs: fix AIM7 regression")
> 
> Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>

This looks OK to me. Feel free to add:

Reviewed-by: Matthew Bobrowski <mbobrowski@mbobrowski.org>

/M