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From: Minchan Kim <minchan@kernel.org>
To: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Huangzhaoyang <huangzhaoyang@gmail.com>,
	Zhaoyang Huang <zhaoyang.huang@unisoc.com>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	Nitin Gupta <ngupta@vflare.org>
Subject: Re: [PATCH] driver: zram: fix wrong counting on pages_store
Date: Mon, 26 Jul 2021 10:53:52 -0700	[thread overview]
Message-ID: <YP72sNSOVwgnQzqo@google.com> (raw)
In-Reply-To: <YP4PjMnw1OZtARQC@google.com>

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.

  reply	other threads:[~2021-07-26 17:53 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 [this message]
2021-07-27  1:32     ` Zhaoyang Huang
2021-07-27  5:45       ` Zhaoyang Huang

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