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From: Theodore Ts'o <tytso@mit.edu>
To: "Lukáš Czerner" <lczerner@redhat.com>
Cc: Namjae Jeon <namjae.jeon@samsung.com>,
	linux-ext4 <linux-ext4@vger.kernel.org>,
	Ashish Sangwan <a.sangwan@samsung.com>
Subject: Re: [PATCH 1/2] ext4: introduce new i_write_mutex to protect fallocate
Date: Thu, 29 May 2014 12:28:10 -0400	[thread overview]
Message-ID: <20140529162810.GG25041@thunk.org> (raw)
In-Reply-To: <alpine.LFD.2.00.1405291439340.18491@localhost.localdomain>

On Thu, May 29, 2014 at 02:42:04PM +0200, Lukáš Czerner wrote:
> 
> I wonder what is the performance impact of this change ? Especially
> since we're not longer taking the lock only in unaligned aio/dio
> case but in all cases ?

Thinking about this some more, this is also going to break parallel
writes, which would be unfortunate.  We might want to change this to
using a rw mutex, where writes take a shared lock, and require
fallocate to take an exclusive lock....

				- Ted
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  reply	other threads:[~2014-05-29 16:28 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-05-13  0:19 [PATCH 1/2] ext4: introduce new i_write_mutex to protect fallocate Namjae Jeon
2014-05-26 16:29 ` Theodore Ts'o
2014-05-27  1:59   ` Theodore Ts'o
2014-05-27  2:12     ` Namjae Jeon
2014-05-29 12:42 ` Lukáš Czerner
2014-05-29 16:28   ` Theodore Ts'o [this message]
2014-05-31  6:45     ` Namjae Jeon
2014-06-02 14:38       ` Theodore Ts'o
2014-06-03  6:04         ` Namjae Jeon
2014-06-03 10:49           ` Lukáš Czerner
2014-06-03 15:19           ` Theodore Ts'o
2014-06-04  5:58             ` Namjae Jeon
2014-06-08  2:48               ` Theodore Ts'o

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