From: Andrew Morton <akpm@linux-foundation.org>
To: Minchan Kim <minchan@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Subject: Re: [PATCH v2 6/7] zram: add bd_stat statistics
Date: Wed, 28 Nov 2018 15:30:21 -0800 [thread overview]
Message-ID: <20181128153021.3f125ed82df68a29e25ce428@linux-foundation.org> (raw)
In-Reply-To: <20181127020754.GB237537@google.com>
On Tue, 27 Nov 2018 11:07:54 +0900 Minchan Kim <minchan@kernel.org> wrote:
> On Mon, Nov 26, 2018 at 12:58:33PM -0800, Andrew Morton wrote:
> > On Mon, 26 Nov 2018 17:28:12 +0900 Minchan Kim <minchan@kernel.org> wrote:
> >
> > > +File /sys/block/zram<id>/bd_stat
> > > +
> > > +The stat file represents device's backing device statistics. It consists of
> > > +a single line of text and contains the following stats separated by whitespace:
> > > + bd_count size of data written in backing device.
> > > + Unit: pages
> > > + bd_reads the number of reads from backing device
> > > + Unit: pages
> > > + bd_writes the number of writes to backing device
> > > + Unit: pages
> >
> > Using `pages' is a bad choice. And I assume this means that
> > writeback_limit is in pages as well, which is worse.
> >
> > Page sizes are not constant! We want userspace which was developed on
> > 4k pagesize to work the same on 64k pagesize.
> >
> > Arguably, we could require that well-written userspace remember to use
> > getpagesize(). However we have traditionally tried to avoid that by
> > performing the pagesize normalization within the kernel.
>
> zram works based on page so I used that term but I agree it's rather
> vague. If there is no objection, I will use (Unit: 4K) instead of
> (Unit: pages).
Is that still true if PAGE_SIZE=64k?
next prev parent reply other threads:[~2018-11-28 23:30 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-26 8:28 [PATCH v2 0/7] zram idle page writeback Minchan Kim
2018-11-26 8:28 ` [PATCH v2 1/7] zram: fix lockdep warning of free block handling Minchan Kim
2018-11-26 20:49 ` Andrew Morton
2018-11-27 2:05 ` Minchan Kim
2018-11-26 8:28 ` [PATCH v2 2/7] zram: fix double free backing device Minchan Kim
2018-11-26 8:28 ` [PATCH v2 3/7] zram: refactoring flags and writeback stuff Minchan Kim
2018-11-26 8:28 ` [PATCH v2 4/7] zram: introduce ZRAM_IDLE flag Minchan Kim
2018-11-26 8:28 ` [PATCH v2 5/7] zram: support idle/huge page writeback Minchan Kim
2018-11-26 9:47 ` Joey Pabalinas
2018-11-26 13:44 ` Joey Pabalinas
2018-11-27 2:13 ` Minchan Kim
2018-11-27 2:53 ` Joey Pabalinas
2018-11-26 8:28 ` [PATCH v2 6/7] zram: add bd_stat statistics Minchan Kim
2018-11-26 20:58 ` Andrew Morton
2018-11-27 2:07 ` Minchan Kim
2018-11-28 23:30 ` Andrew Morton [this message]
2018-11-29 1:45 ` Minchan Kim
2018-11-26 8:28 ` [PATCH v2 7/7] zram: writeback throttle Minchan Kim
2018-11-26 20:54 ` Andrew Morton
2018-11-27 2:08 ` Minchan Kim
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=20181128153021.3f125ed82df68a29e25ce428@linux-foundation.org \
--to=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=minchan@kernel.org \
--cc=sergey.senozhatsky.work@gmail.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).