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From: Jaegeuk Kim <jaegeuk@kernel.org>
To: 李扬韬 <frank.li@vivo.com>
Cc: Chao Yu <chao@kernel.org>,
	linux-f2fs-devel@lists.sourceforge.net,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] f2fs: add sysfs nodes to get discard information
Date: Mon, 16 Aug 2021 17:16:24 -0700	[thread overview]
Message-ID: <YRr/2DM84TishToA@google.com> (raw)
In-Reply-To: <AGwAWQBVD3NfsYDCdBIWb4qP.3.1629094420548.Hmail.frank.li@vivo.com>

On 08/16, 李扬韬 wrote:
> >>>> I've added new sysfs nodes to show discard stat since mount, which
> >>>> will help us analyze whether the performance problem is related to
> >>>> discard.
> >>>>
> >>>> issued_discard  - Shows the number of issued discard
> >>>> queued_discard  - Shows the number of cached discard cmd count
> >>>> discard_cmd_cnt - Shows the number of cached discard cmd count
> >>>> undiscard_blks  - Shows the number of undiscard blocks
> >>>
> >>> We have exported them in debugfs, can you use that?
> >>>
> >>> Thanks,
> >> 
> >> But now Android is forbidden to open debugfs, and in fact we have not
> >> opened this configuration for a long time.
> >
> >Weren't them be used for debug purpose? can you please explain more about
> >your use case?
> 
> During long-term aging test or normal use, sometimes there will be performance
> degradation problems. It may be caused by storage, or it may be caused by the
> filesystem. For example, the filesystem accumulates a large number of undiscard
>  blocks. Although there is some remaining space, the androidbench test will
> show performance degradation. Therefore, it is necessary to export information
> related to discard so that we can confirm this situation.

I think you can mount debugfs for that case?

> 
> Thx,
> 
> 

  reply	other threads:[~2021-08-17  0:16 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-14 17:58 Yangtao Li
2021-08-14 17:58 ` [PATCH 2/2] f2fs: fix description about main_blkaddr node Yangtao Li
2021-08-16  2:37   ` Chao Yu
2021-08-16  2:35 ` [PATCH 1/2] f2fs: add sysfs nodes to get discard information Chao Yu
2021-08-16  2:42   ` 李扬韬
2021-08-16  4:15     ` Chao Yu
2021-08-16  6:13       ` 李扬韬
2021-08-17  0:16         ` Jaegeuk Kim [this message]
2021-08-19  4:49         ` Chao Yu

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