From: Johannes Weiner <hannes@cmpxchg.org>
To: Minchan Kim <minchan@kernel.org>
Cc: Shaohua Li <shli@fb.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Kernel-team@fb.com, mhocko@suse.com, hughd@google.com,
riel@redhat.com, mgorman@techsingularity.net,
akpm@linux-foundation.org
Subject: Re: [PATCH V4 4/6] mm: reclaim MADV_FREE pages
Date: Fri, 24 Feb 2017 10:36:55 -0500 [thread overview]
Message-ID: <20170224153655.GA20092@cmpxchg.org> (raw)
In-Reply-To: <20170224021218.GD9818@bbox>
On Fri, Feb 24, 2017 at 11:12:18AM +0900, Minchan Kim wrote:
> > @@ -1525,8 +1531,8 @@ int try_to_unmap(struct page *page, enum ttu_flags flags)
> >
> > if (ret != SWAP_MLOCK && !page_mapcount(page)) {
> > ret = SWAP_SUCCESS;
> > - if (rp.lazyfreed && !PageDirty(page))
> > - ret = SWAP_LZFREE;
> > + if (rp.lazyfreed && PageDirty(page))
> > + ret = SWAP_DIRTY;
>
> Hmm, I don't understand why we need to introduce new return value.
> Can't we set SetPageSwapBacked and return SWAP_FAIL in try_to_unmap_one?
I think that's a bad idea. A function called "try_to_unmap" shouldn't
have as a side effect that it changes the page's LRU type in an error
case. Let try_to_unmap be about unmapping the page. If it fails, make
it report why and let the caller deal with the fallout. Any LRU fixups
are much better placed in vmscan.c.
next prev parent reply other threads:[~2017-02-24 15:44 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-22 18:50 [PATCH V4 0/6] mm: fix some MADV_FREE issues Shaohua Li
2017-02-22 18:50 ` [PATCH V4 1/6] mm: delete unnecessary TTU_* flags Shaohua Li
2017-02-23 15:35 ` Johannes Weiner
2017-02-24 1:25 ` Minchan Kim
2017-02-24 3:29 ` Hillf Danton
2017-02-22 18:50 ` [PATCH V4 2/6] mm: don't assume anonymous pages have SwapBacked flag Shaohua Li
2017-02-22 18:50 ` [PATCH V4 3/6] mm: move MADV_FREE pages into LRU_INACTIVE_FILE list Shaohua Li
2017-02-23 15:58 ` Johannes Weiner
2017-02-23 16:26 ` Shaohua Li
2017-02-23 18:22 ` Johannes Weiner
2017-02-23 19:04 ` Shaohua Li
2017-02-24 1:49 ` Minchan Kim
2017-02-24 6:15 ` Shaohua Li
2017-02-24 23:37 ` Minchan Kim
2017-02-22 18:50 ` [PATCH V4 4/6] mm: reclaim MADV_FREE pages Shaohua Li
2017-02-23 16:13 ` Johannes Weiner
2017-02-23 17:19 ` Shaohua Li
2017-02-24 2:12 ` Minchan Kim
2017-02-24 6:14 ` Shaohua Li
2017-02-24 15:36 ` Johannes Weiner [this message]
2017-02-24 23:26 ` Minchan Kim
2017-02-22 18:50 ` [PATCH V4 5/6] mm: enable MADV_FREE for swapless system Shaohua Li
2017-02-22 18:50 ` [PATCH V4 6/6] proc: show MADV_FREE pages info in smaps Shaohua Li
2017-02-23 16:16 ` Johannes Weiner
2017-02-24 2:13 ` Minchan Kim
2017-02-24 17:08 ` Dave Hansen
2017-02-24 21:47 ` Shaohua Li
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=20170224153655.GA20092@cmpxchg.org \
--to=hannes@cmpxchg.org \
--cc=Kernel-team@fb.com \
--cc=akpm@linux-foundation.org \
--cc=hughd@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mgorman@techsingularity.net \
--cc=mhocko@suse.com \
--cc=minchan@kernel.org \
--cc=riel@redhat.com \
--cc=shli@fb.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