Re: [f2fs-dev] [PATCH] f2fs: fix double count on issued discard commands

From	Daeho Jeong <daeho.jeong@samsung.com>
Newsgroups	linux.kernel
Subject	Re: [f2fs-dev] [PATCH] f2fs: fix double count on issued discard commands
Date	2017-09-12 06:40 +0200
Message-ID	<uoL9n-4Vo-1@gated-at.bofh.it> (permalink)
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> Yeah, that's exactly like what I made a mistake before.
> I should have mentioned that earlier. :)

Or I think the previous code which used "iter++" might be right.
You might just want to check the fixed number of small discards, DISCARD_ISSUE_RATE,
when issue_cond is "true".

Anyways, I have another question about this function.
How about just issuing, not checking whether it is idle, the fixed number of small
discards, DISCARD_ISSUE_RATE, when issue_cond is "true".
Actually, the discard commands will be issued as "asynchronous" requests,
which has a low priority in the I/O scheduler,
so the performance degradation of other threads by doing this will not be much severe,
but we can make the performance of the storage device better even if there is no idle.

I am just worried about the storage device I/O performance gets worse 
under I/O intensive senario where there is no idle

Thanks,

Thread

[PATCH] f2fs: fix double count on issued discard commands Jaegeuk Kim <jaegeuk@kernel.org> - 2017-09-11 05:40 +0200
  Re: [f2fs-dev] [PATCH] f2fs: fix double count on issued discard  commands Chao Yu <yuchao0@huawei.com> - 2017-09-12 04:00 +0200
    Re: [f2fs-dev] [PATCH] f2fs: fix double count on issued discard  commands Chao Yu <yuchao0@huawei.com> - 2017-09-12 06:00 +0200
      Re: [f2fs-dev] [PATCH] f2fs: fix double count on issued discard  commands Jaegeuk Kim <jaegeuk@kernel.org> - 2017-09-12 06:30 +0200
        Re: [f2fs-dev] [PATCH] f2fs: fix double count on issued discard  commands Daeho Jeong <daeho.jeong@samsung.com> - 2017-09-12 06:40 +0200
          Re: [f2fs-dev] [PATCH] f2fs: fix double count on issued discard  commands Jaegeuk Kim <jaegeuk@kernel.org> - 2017-09-12 19:20 +0200
          Re: [f2fs-dev] [PATCH] f2fs: fix double count on issued discard  commands Chao Yu <yuchao0@huawei.com> - 2017-09-13 09:20 +0200
            Re: [f2fs-dev] [PATCH] f2fs: fix double count on issued discard  commands Daeho Jeong <daeho.jeong@samsung.com> - 2017-09-13 10:50 +0200

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