From: Christoph Lameter <cl@linux.com>
To: Geliang Tang <geliangtang@163.com>
Cc: Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] mm/slab.c: use list_{empty_careful,last_entry} in drain_freelist
Date: Thu, 3 Dec 2015 08:53:21 -0600 (CST) [thread overview]
Message-ID: <alpine.DEB.2.20.1512030850390.7483@east.gentwo.org> (raw)
In-Reply-To: <3ea815dc52bf1a2bb5e324d7398315597900be84.1449151365.git.geliangtang@163.com>
On Thu, 3 Dec 2015, Geliang Tang wrote:
> while (nr_freed < tofree && !list_empty(&n->slabs_free)) {
>
> spin_lock_irq(&n->list_lock);
> - p = n->slabs_free.prev;
> - if (p == &n->slabs_free) {
> + if (list_empty_careful(&n->slabs_free)) {
We have taken the lock. Why do we need to be "careful"? list_empty()
shoudl work right?
> spin_unlock_irq(&n->list_lock);
> goto out;
> }
>
> - page = list_entry(p, struct page, lru);
> + page = list_last_entry(&n->slabs_free, struct page, lru);
last???
Would the the other new function that returns NULL on the empty list or
the pointer not be useful here too and save some code?
This patch seems to make it difficult to understand the code.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2015-12-03 14:54 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-02 15:46 [PATCH 1/3] mm/slab: use list_first_entry_or_null() Geliang Tang
2015-12-02 15:46 ` [PATCH 2/3] mm/slab: use list_for_each_entry in cache_flusharray Geliang Tang
2015-12-02 15:46 ` [PATCH 3/3] mm/slab: use list_{empty_careful,last_entry} in drain_freelist Geliang Tang
2015-12-02 16:06 ` Christoph Lameter
2015-12-03 14:07 ` [PATCH v2] mm/slab.c: " Geliang Tang
2015-12-03 14:53 ` Christoph Lameter [this message]
2015-12-04 13:43 ` Geliang Tang
2015-12-04 16:16 ` Christoph Lameter
2015-12-05 2:36 ` Geliang Tang
2015-12-02 15:58 ` [PATCH 2/3] mm/slab: use list_for_each_entry in cache_flusharray Christoph Lameter
2015-12-02 15:57 ` [PATCH 1/3] mm/slab: use list_first_entry_or_null() Christoph Lameter
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=alpine.DEB.2.20.1512030850390.7483@east.gentwo.org \
--to=cl@linux.com \
--cc=akpm@linux-foundation.org \
--cc=geliangtang@163.com \
--cc=iamjoonsoo.kim@lge.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=penberg@kernel.org \
--cc=rientjes@google.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