From: Zhaoyang Huang <huangzhaoyang@gmail.com>
To: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>,
Zhaoyang Huang <zhaoyang.huang@unisoc.com>,
"open list:MEMORY MANAGEMENT" <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
Nitin Gupta <ngupta@vflare.org>
Subject: Re: [PATCH] driver: zram: fix wrong counting on pages_store
Date: Tue, 27 Jul 2021 13:45:04 +0800 [thread overview]
Message-ID: <CAGWkznGt9hWGM4KF-0WX4noe=piB4==T4cVuSETDGAsn7Xgi=Q@mail.gmail.com> (raw)
In-Reply-To: <CAGWkznFifWQSMAoz-qD2M_qnZL=qi8XsJPVxet6Cbt_euD4eAg@mail.gmail.com>
On Tue, Jul 27, 2021 at 9:32 AM Zhaoyang Huang <huangzhaoyang@gmail.com> wrote:
>
> On Tue, Jul 27, 2021 at 1:53 AM Minchan Kim <minchan@kernel.org> wrote:
> >
> > On Mon, Jul 26, 2021 at 10:27:40AM +0900, Sergey Senozhatsky wrote:
> > > On (21/07/20 14:47), Huangzhaoyang wrote:
> > > > It makes the statistic confused when counting pages_store in during writeback.
> > > > pages_store should just reflect the swapped pages on ZRAM, while bd_writes be
> > > > responsible for writeback things.
> > > >
> > > > Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
> > > > ---
> > > > drivers/block/zram/zram_drv.c | 1 -
> > > > 1 file changed, 1 deletion(-)
> > > >
> > > > diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
> > > > index cf8deec..6bdaa9d 100644
> > > > --- a/drivers/block/zram/zram_drv.c
> > > > +++ b/drivers/block/zram/zram_drv.c
> > > > @@ -765,7 +765,6 @@ static ssize_t writeback_store(struct device *dev,
> > > > zram_set_flag(zram, index, ZRAM_WB);
> > > > zram_set_element(zram, index, blk_idx);
> > > > blk_idx = 0;
> > > > - atomic64_inc(&zram->stats.pages_stored);
> > >
> > > Yeah, I think we don't need it here.
> > >
> > > Minchan, what do you think?
> >
> > What pages_stored currently represents is orig_data_size from mm_stat
> >
> > ================ =============================================================
> > orig_data_size uncompressed size of data stored in this disk.
> > Unit: bytes
> >
> > Thus, if we don't increase it after zram_free_page, it loses what's
> > the original data size which would be important to calculate
> > compression ratio along with compr_data_size.
> zram_free_page?? What the commit try to fix is pages_stored being
> increased incorrectly in writeback_store, which will lead to wrong
> statistic on orig size of ZRAM.
OK, if I understand right, I think what you mean is the page count
corresponding to SWAP should be still available even if it is written
back to the backing dev.So we need to increase page_stored again after
zram_free_page free it.
prev parent reply other threads:[~2021-07-27 5:45 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-20 6:47 [PATCH] driver: zram: fix wrong counting on pages_store Huangzhaoyang
2021-07-25 1:19 ` [Resend PATCH] " Zhaoyang Huang
2021-07-26 1:27 ` [PATCH] " Sergey Senozhatsky
2021-07-26 17:53 ` Minchan Kim
2021-07-27 1:32 ` Zhaoyang Huang
2021-07-27 5:45 ` Zhaoyang Huang [this message]
Reply instructions:
You may reply publicly 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='CAGWkznGt9hWGM4KF-0WX4noe=piB4==T4cVuSETDGAsn7Xgi=Q@mail.gmail.com' \
--to=huangzhaoyang@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=minchan@kernel.org \
--cc=ngupta@vflare.org \
--cc=senozhatsky@chromium.org \
--cc=zhaoyang.huang@unisoc.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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).