From: Christoph Hellwig <hch@infradead.org>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH] blk-mq: use __smp_call_function_single directly
Date: Thu, 9 Jan 2014 10:35:07 -0800 [thread overview]
Message-ID: <20140109183507.GA23826@infradead.org> (raw)
In-Reply-To: <52CDC3A3.5050203@kernel.dk>
On Wed, Jan 08, 2014 at 02:31:15PM -0700, Jens Axboe wrote:
> On 01/08/2014 10:33 AM, Christoph Hellwig wrote:
> > __smp_call_function_single already avoids multiple IPIs by internally
> > queing up the items, and now also is available for non-SMP builds as
> > a trivially correct stub, so there is no need to wrap it. If the
> > additional lock roundtrip cause problems my patch to convert the
> > generic IPI code to llists is waiting to get merged will fix it.
>
> Thanks Christoph, applied it.
Btw, the same should be done to the null_blk ipi completion
path in theory. But given that it always tries to IPI the local
CPU __smp_call_function_single turns into a simple indirect function
call, so I don't really understand the point of that code path at all.
next prev parent reply other threads:[~2014-01-09 18:35 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-08 17:33 [PATCH] blk-mq: use __smp_call_function_single directly Christoph Hellwig
2014-01-08 21:31 ` Jens Axboe
2014-01-09 18:35 ` Christoph Hellwig [this message]
2014-01-10 2:34 ` Jens Axboe
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