From: Andi Kleen <ak@linux.intel.com>
To: kemi <kemi.wang@intel.com>
Cc: Jens Axboe <axboe@kernel.dk>, Jan Kara <jack@suse.cz>,
Darrick J Wong <darrick.wong@oracle.com>,
Eric Biggers <ebiggers@google.com>,
Andreas Gruenbacher <agruenba@redhat.com>,
Jeff Layton <jlayton@redhat.com>,
Dave <dave.hansen@linux.intel.com>,
Andi Kleen <andi.kleen@intel.com>,
Tim Chen <tim.c.chen@intel.com>,
Ying Huang <ying.huang@intel.com>, Aaron Lu <aaron.lu@intel.com>,
Linux Kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] buffer: Avoid setting buffer bits that are already set
Date: Mon, 23 Oct 2017 18:21:21 -0700 [thread overview]
Message-ID: <87h8upxrvy.fsf@linux.intel.com> (raw)
In-Reply-To: <f475ae05-733d-b0a2-cadc-a5913f521153@intel.com> (kemi's message of "Tue, 24 Oct 2017 08:52:22 +0800")
kemi <kemi.wang@intel.com> writes:
>
> I'll see if I can find some
>> time to implement the above in a nice way.
>
> Agree. Maybe something like test_and_set_bit() would be more suitable.
test_and_set_bit is a very different operation for the CPU because
it is atomic for both. But we want the initial read to not
be atomic.
If you add special functions use a different variant that is only
atomic for the set.
-Andi
next prev parent reply other threads:[~2017-10-24 1:21 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-23 15:27 [PATCH] buffer: Avoid setting buffer bits that are already set Kemi Wang
2017-10-23 16:19 ` Jens Axboe
2017-10-24 0:52 ` kemi
2017-10-24 1:21 ` Andi Kleen [this message]
2017-10-24 1:25 ` kemi
2017-10-24 13:50 ` Jens Axboe
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