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From: tada keisuke <keisuke1.tada@kioxia.com>
To: Yu Kuai <yukuai1@huaweicloud.com>, "song@kernel.org" <song@kernel.org>
Cc: "linux-raid@vger.kernel.org" <linux-raid@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"yukuai (C)" <yukuai3@huawei.com>
Subject: Re: [PATCH 00/11] md: avoid counter operation conflicts
Date: Wed, 27 Mar 2024 01:27:19 +0000	[thread overview]
Message-ID: <481dc71231494b729b13dcc7392deb00@kioxia.com> (raw)
In-Reply-To: <140c7f16-4c2a-390a-7021-53d3723626ec@huaweicloud.com>

>> Currently, active_aligned_reads and nr_pending used as counters are atomic types.
>> Therefore, when inc/dec in a multi-core results in conflicts.
>
> I don't uderstand what's the problem here, what's wrong with atomic
> types in a multi-core system?

Hi Kuai

This patch is not a fix for the problem, but an improvement.
This patch makes the counter inc/dec faster.

For the same reason, active_io was changed from atomic_t to percpu_ref.
https://marc.info/?l=linux-raid&m=167514225920879

Thanks,
Keisuke


  reply	other threads:[~2024-03-27  1:27 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-03-26 10:29 [PATCH 00/11] md: avoid counter operation conflicts tada keisuke
2024-03-26 14:01 ` Yu Kuai
2024-03-27  1:27   ` tada keisuke [this message]
2024-04-10 21:13 ` Song Liu

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