From: Andrew Morton <akpm@linux-foundation.org>
To: Hisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp>
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [RESEND] [PATCH] lseek: remove i_mutex
Date: Thu, 5 Feb 2009 12:05:19 -0800 [thread overview]
Message-ID: <20090205120519.a62e8c4f.akpm@linux-foundation.org> (raw)
In-Reply-To: <6.0.0.20.2.20090203165430.06ae1cd8@172.19.0.2>
On Tue, 03 Feb 2009 17:04:40 +0900
Hisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp> wrote:
> I removed i_mutex from generic_file_llseek.
> I think that the reason of protecting lseek with i_mutex is just
> touching i_size atomically.
>
> So I introduce i_size_read here so i_mutex is no longer needed.
>
> Following patch removes i_mutex from generic_file_llseek, and deletes
> generic_file_llseek_nolock totally.
>
> Currently there is i_mutex contention not only around lseek, but also fsync or write.
> So, I think we can mitigate i_mutex contention between fsync lseek and write by
> removing i_mutex.
Prior to this change, generic_file_llseek() modified file->f_pos
atomically with respect to other i_mutex holders.
After this change, it doesn't.
next prev parent reply other threads:[~2009-02-05 20:05 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-03 8:04 [RESEND] [PATCH] lseek: remove i_mutex Hisashi Hifumi
2009-02-05 20:05 ` Andrew Morton [this message]
2009-02-06 0:20 ` Hisashi Hifumi
2009-02-06 0:33 ` Andrew Morton
-- strict thread matches above, loose matches on Subject: below --
2009-05-14 0:26 [RESEND][PATCH] " Hisashi Hifumi
2009-05-14 5:57 ` Eric Dumazet
2009-06-25 4:41 Hisashi Hifumi
2009-06-25 4:54 ` Al Viro
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