From: Jens Axboe <axboe@kernel.dk>
To: Ming Lei <ming.lei@redhat.com>,
linux-kernel@vger.kernel.org, linux-block@vger.kernel.org
Cc: Sagi Grimberg <sagi@grimberg.me>, Tejun Heo <tj@kernel.org>,
Christoph Hellwig <hch@lst.de>,
Bart Van Assche <bvanassche@acm.org>
Subject: Re: [PATCH V2 0/2] percpu_ref & block: reduce memory footprint of percpu_ref in fast path
Date: Wed, 2 Sep 2020 08:02:30 -0600 [thread overview]
Message-ID: <4ce7b53b-2c42-3814-fa0a-5324aca6aae0@kernel.dk> (raw)
In-Reply-To: <20200902122643.634143-1-ming.lei@redhat.com>
On 9/2/20 6:26 AM, Ming Lei wrote:
> Hi,
>
> The 1st patch removes memory footprint of percpu_ref in fast path
> from 7 words to 2 words, since it is often used in fast path and
> embedded in user struct.
>
> The 2nd patch moves .q_usage_counter to 1st cacheline of
> 'request_queue'.
>
> Simple test on null_blk shows ~2% IOPS boost on one 16cores(two threads
> per core) machine, dual socket/numa.
>
> V2:
> - pass 'gfp' to kzalloc() for fixing block/027 failure reported by
> kernel test robot
> - protect percpu_ref_is_zero() with destroying percpu-refcount by
> spin lock
>
> Ming Lei (2):
> percpu_ref: reduce memory footprint of percpu_ref in fast path
> block: move 'q_usage_counter' into front of 'request_queue'
Applied, thanks.
--
Jens Axboe
prev parent reply other threads:[~2020-09-02 14:49 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-02 12:26 [PATCH V2 0/2] percpu_ref & block: reduce memory footprint of percpu_ref in fast path Ming Lei
2020-09-02 12:26 ` [PATCH V2 1/2] percpu_ref: " Ming Lei
2020-09-02 13:44 ` Christoph Hellwig
2020-09-02 12:26 ` [PATCH V2 2/2] block: move 'q_usage_counter' into front of 'request_queue' Ming Lei
2020-09-02 13:44 ` Christoph Hellwig
2020-09-02 14:02 ` Jens Axboe [this message]
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