From: Jens Axboe <axboe@kernel.dk>
To: Sagi Grimberg <sagi@grimberg.me>,
Max Gurtovoy <mgurtovoy@nvidia.com>,
linux-nvme@lists.infradead.org
Cc: Christoph Hellwig <hch@lst.de>, Keith Busch <kbusch@kernel.org>,
Chaitanya Kulkarni <Chaitanya.Kulkarni@wdc.com>,
linux-block@vger.kernel.org, Hannes Reinecke <hare@suse.de>
Subject: Re: [PATCH rfc] nvme: support io stats on the mpath device
Date: Thu, 29 Sep 2022 09:05:51 -0600 [thread overview]
Message-ID: <04b39974-6b55-7aca-70de-4a567f2eac8f@kernel.dk> (raw)
In-Reply-To: <a3d619a3-ccae-69ea-3e2c-9acff7b97d92@grimberg.me>
On 9/29/22 3:59 AM, Sagi Grimberg wrote:
>> 3. Do you have some performance numbers (we're touching the fast path here) ?
>
> This is pretty light-weight, accounting is per-cpu and only wrapped by
> preemption disable. This is a very small price to pay for what we gain.
Is it? Enabling IO stats for normal devices has a very noticeable impact
on performance at the higher end of the scale. So much so that I've
contemplated how we can make this less expensive than it currently is.
--
Jens Axboe
next prev parent reply other threads:[~2022-09-29 15:06 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-28 19:55 [PATCH rfc 0/1] nvme-mpath: Add IO stats support Sagi Grimberg
2022-09-28 19:55 ` [PATCH rfc] nvme: support io stats on the mpath device Sagi Grimberg
2022-09-29 9:42 ` Max Gurtovoy
2022-09-29 9:59 ` Sagi Grimberg
2022-09-29 10:25 ` Max Gurtovoy
2022-09-29 15:03 ` Keith Busch
2022-09-29 16:14 ` Sagi Grimberg
2022-09-30 15:21 ` Keith Busch
2022-10-03 8:09 ` Sagi Grimberg
2022-10-25 15:30 ` Christoph Hellwig
2022-10-25 15:58 ` Sagi Grimberg
2022-10-30 16:22 ` Christoph Hellwig
2022-09-29 16:32 ` Sagi Grimberg
2022-09-30 15:16 ` Keith Busch
2022-10-03 8:02 ` Sagi Grimberg
2022-10-03 9:32 ` Sagi Grimberg
2022-09-29 15:05 ` Jens Axboe [this message]
2022-09-29 16:25 ` Sagi Grimberg
2022-09-30 0:08 ` Jens Axboe
2022-10-03 8:35 ` Sagi Grimberg
2022-09-29 10:04 ` Sagi Grimberg
2022-09-29 15:07 ` Jens Axboe
2022-10-03 8:38 ` Sagi Grimberg
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