From: Andrew Morton <akpm@linux-foundation.org>
To: Christoph Hellwig <hch@lst.de>
Cc: baoquan.he@linux.dev, chrisl@kernel.org, usama.arif@linux.dev,
kasong@tencent.com, nphamcs@gmail.com, shikemeng@huaweicloud.com,
youngjun.park@lge.com, linux-mm@kvack.org
Subject: Re: [PATCH 7/7] mm/vmstat: add NRSWP{IN,OUT} counters
Date: Tue, 21 Jul 2026 17:47:16 -0700 [thread overview]
Message-ID: <20260721174716.c35ea9ab0db2b8d546135fba@linux-foundation.org> (raw)
In-Reply-To: <20260706132206.935272-8-hch@lst.de>
On Mon, 6 Jul 2026 15:21:59 +0200 Christoph Hellwig <hch@lst.de> wrote:
> Count how many swap I/Os we cause. Due to batching this can be different
> than the current counter number of pages written/read, and tracking this
> information is useful to see how efficient the batching is.
>
> The counters are added at the end of enum vm_event_item and the
> vmstat_text array under the assumption that the order of fields in
> /proc/vmstat is an ABI. If that is not the case, they could be grouped
> with the other swap counters.
Well. We've always taken the point of view that /proc/vmstat is a
developer dumping ground so things can be added, removed and altered.
Failing to Document/ the file is our cryptic way of telling users this ;)
IOW, it should be in debugfs, but it predates debugfs.
That being said, I'm sure users are poking at it in all sorts of ways
so let's not churn things without good reason.
That being said, it's all "name value" pairs, so the ordering of things
shouldn't matter.
next prev parent reply other threads:[~2026-07-22 0:47 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-06 13:21 better block swap batching and a different take on swap_ops v3 Christoph Hellwig
2026-07-06 13:21 ` [PATCH 1/7] shmem: provide a shmem_write_folio wrapper Christoph Hellwig
2026-07-07 2:40 ` Baolin Wang
2026-07-06 13:21 ` [PATCH 2/7] mm/swap: introduce struct swap_io_ctx Christoph Hellwig
2026-07-06 13:21 ` [PATCH 3/7] mm/swap: also use struct swap_iocb for block I/O Christoph Hellwig
2026-07-06 13:21 ` [PATCH 4/7] mm/swap: remove count_swpout_vm_event Christoph Hellwig
2026-07-06 13:21 ` [PATCH 5/7] mm/swap: use swap_ops to register swap device's methods Christoph Hellwig
2026-07-06 13:21 ` [PATCH 6/7] mm/swap: remove SWP_FS_OPS Christoph Hellwig
2026-07-06 13:21 ` [PATCH 7/7] mm/vmstat: add NRSWP{IN,OUT} counters Christoph Hellwig
[not found] ` <aln4IQ0d1ASf50fz@KASONG-MC4>
2026-07-21 4:29 ` Christoph Hellwig
2026-07-22 0:47 ` Andrew Morton [this message]
2026-07-06 17:21 ` better block swap batching and a different take on swap_ops v3 Andrew Morton
2026-07-07 5:06 ` Christoph Hellwig
2026-07-09 8:53 ` Matthew Brost
-- strict thread matches above, loose matches on Subject: below --
2026-07-10 6:39 better block swap batching and a different take on swap_ops v4 Christoph Hellwig
2026-07-10 6:39 ` [PATCH 7/7] mm/vmstat: add NRSWP{IN,OUT} counters Christoph Hellwig
2026-07-13 9:33 better block swap batching and a different take on swap_ops v5 Christoph Hellwig
2026-07-13 9:33 ` [PATCH 7/7] mm/vmstat: add NRSWP{IN,OUT} counters Christoph Hellwig
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=20260721174716.c35ea9ab0db2b8d546135fba@linux-foundation.org \
--to=akpm@linux-foundation.org \
--cc=baoquan.he@linux.dev \
--cc=chrisl@kernel.org \
--cc=hch@lst.de \
--cc=kasong@tencent.com \
--cc=linux-mm@kvack.org \
--cc=nphamcs@gmail.com \
--cc=shikemeng@huaweicloud.com \
--cc=usama.arif@linux.dev \
--cc=youngjun.park@lge.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.