Linux-f2fs-devel Archive on lore.kernel.org
 help / color / Atom feed
From: Jaegeuk Kim <jaegeuk@kernel.org>
To: Chao Yu <yuchao0@huawei.com>
Cc: linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net
Subject: Re: [f2fs-dev] [PATCH 1/2] f2fs: do not select same victim right again
Date: Mon, 16 Sep 2019 08:37:36 -0700
Message-ID: <20190916153736.GA2493@jaegeuk-macbookpro.roam.corp.google.com> (raw)
In-Reply-To: <27725e65-53fe-5731-0201-9959b8ef6b49@huawei.com>

On 09/16, Chao Yu wrote:
> On 2019/9/9 20:04, Jaegeuk Kim wrote:
> > On 09/09, Chao Yu wrote:
> >> On 2019/9/9 16:06, Jaegeuk Kim wrote:
> >>> On 09/09, Chao Yu wrote:
> >>>> On 2019/9/9 9:25, Jaegeuk Kim wrote:
> >>>>> GC must avoid select the same victim again.
> >>>>
> >>>> Blocks in previous victim will occupy addition free segment, I doubt after this
> >>>> change, FGGC may encounter out-of-free space issue more frequently.
> >>>
> >>> Hmm, actually this change seems wrong by sec_usage_check().
> >>> We may be able to avoid this only in the suspicious loop?
> >>>
> >>> ---
> >>>  fs/f2fs/gc.c | 2 +-
> >>>  1 file changed, 1 insertion(+), 1 deletion(-)
> >>>
> >>> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> >>> index e88f98ddf396..5877bd729689 100644
> >>> --- a/fs/f2fs/gc.c
> >>> +++ b/fs/f2fs/gc.c
> >>> @@ -1326,7 +1326,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
> >>>  		round++;
> >>>  	}
> >>>  
> >>> -	if (gc_type == FG_GC)
> >>> +	if (gc_type == FG_GC && seg_freed)
> >>
> >> That's original solution Sahitya provided to avoid infinite loop of GC, but I
> >> suggest to find the root cause first, then we added .invalid_segmap for that
> >> purpose.
> > 
> > I've checked the Sahitya's patch. So, it seems the problem can happen due to
> > is_alive or atomic_file.
> 
> For some conditions, this doesn't help, for example, two sections contain the
> same fewest valid blocks, it will cause to loop selecting them if it fails to
> migrate blocks.
> 
> How about keeping it as it is to find potential bug.

I think it'd be fine to merge this. Could you check the above scenario in more
detail?

Thanks,

> 
> Thanks,
> 
> > 
> >>
> >> Thanks,
> >>
> >>>  		sbi->cur_victim_sec = NULL_SEGNO;
> >>>  
> >>>  	if (sync)
> >>>
> > .
> > 


_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

  reply index

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-09  1:25 Jaegeuk Kim
2019-09-09  1:25 ` [f2fs-dev] [PATCH 2/2] f2fs: avoid infinite GC loop due to stale atomic files Jaegeuk Kim
2019-09-09  3:03   ` Chao Yu
2019-09-09  7:30     ` Jaegeuk Kim
2019-09-09  7:54       ` Chao Yu
2019-09-09  8:01         ` Jaegeuk Kim
2019-09-09  8:05           ` Chao Yu
2019-09-09  8:21             ` Jaegeuk Kim
2019-09-09  8:27               ` Chao Yu
2019-09-09  8:38                 ` Jaegeuk Kim
2019-09-09  8:44                   ` Jaegeuk Kim
2019-09-09 11:26                   ` Chao Yu
2019-09-09 14:34                     ` Jaegeuk Kim
2019-09-10  0:59                       ` Chao Yu
2019-09-10 11:58                         ` Jaegeuk Kim
2019-09-10 12:04                           ` Chao Yu
2019-09-10 12:09                             ` Jaegeuk Kim
2019-09-16  1:15                               ` Chao Yu
2019-09-09  2:56 ` [f2fs-dev] [PATCH 1/2] f2fs: do not select same victim right again Chao Yu
2019-09-09  8:06   ` Jaegeuk Kim
2019-09-09 11:32     ` Chao Yu
2019-09-09 12:04       ` Jaegeuk Kim
2019-09-16  1:22         ` Chao Yu
2019-09-16 15:37           ` Jaegeuk Kim [this message]
2019-09-17  1:42             ` Chao Yu
2019-09-17 20:55               ` Jaegeuk Kim
2019-09-18  1:43                 ` Chao Yu
2019-09-18  3:12                   ` Jaegeuk Kim
2019-09-18  3:26                     ` Chao Yu
2019-09-18 16:47                       ` Jaegeuk Kim
2019-09-19  0:53                         ` Chao Yu
2019-09-19 17:11                           ` Jaegeuk Kim

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190916153736.GA2493@jaegeuk-macbookpro.roam.corp.google.com \
    --to=jaegeuk@kernel.org \
    --cc=linux-f2fs-devel@lists.sourceforge.net \
    --cc=linux-kernel@vger.kernel.org \
    --cc=yuchao0@huawei.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-f2fs-devel Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-f2fs-devel/0 linux-f2fs-devel/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-f2fs-devel linux-f2fs-devel/ https://lore.kernel.org/linux-f2fs-devel \
		linux-f2fs-devel@lists.sourceforge.net linux-f2fs-devel@archiver.kernel.org
	public-inbox-index linux-f2fs-devel

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/net.sourceforge.lists.linux-f2fs-devel


AGPL code for this site: git clone https://public-inbox.org/ public-inbox