From: Al Viro <viro@ZenIV.linux.org.uk>
To: Davidlohr Bueso <dave@stgolabs.net>
Cc: starvik@axis.com, jesper.nilsson@axis.com,
akpm@linux-foundation.org, linux-cris-kernel@axis.com,
linux-kernel@vger.kernel.org, Davidlohr Bueso <dbueso@suse.de>
Subject: Re: [PATCH] arch/cris: use get_user_pages_fast()
Date: Sun, 21 Jan 2018 23:39:43 +0000 [thread overview]
Message-ID: <20180121233943.GO13338@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20180121225929.11782-1-dave@stgolabs.net>
On Sun, Jan 21, 2018 at 02:59:29PM -0800, Davidlohr Bueso wrote:
> Since we currently hold mmap_sem across both gup calls (and
> nothing more), we can substitute it with two _fast()
> alternatives and possibly avoid grabbing the lock.
>
> This was found while adding mmap_sem wrappers, and was also
> previously reported by Al: https://lkml.org/lkml/2017/11/17/777
See commit 9a949e8ff92246c0753b2805c2a001cb991fffe5
Author: Al Viro <viro@zeniv.linux.org.uk>
Date: Sat Nov 18 14:37:46 2017 -0500
cris: switch to get_user_pages_fast()
no point holding ->mmap_sem over both calls.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
in -next...
next prev parent reply other threads:[~2018-01-21 23:39 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-21 22:59 [PATCH] arch/cris: use get_user_pages_fast() Davidlohr Bueso
2018-01-21 23:39 ` Al Viro [this message]
2018-01-21 23:48 ` Davidlohr Bueso
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