From: Christopher Lameter <cl@linux.com>
To: Xunlei Pang <xlpang@linux.alibaba.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Wen Yang <wenyang@linux.alibaba.com>,
Yang Shi <yang.shi@linux.alibaba.com>,
Roman Gushchin <guro@fb.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] mm/slub: Introduce two counters for the partial objects
Date: Tue, 7 Jul 2020 06:59:04 +0000 (UTC) [thread overview]
Message-ID: <alpine.DEB.2.22.394.2007070656120.1587@www.lameter.com> (raw)
In-Reply-To: <1593678728-128358-1-git-send-email-xlpang@linux.alibaba.com>
On Thu, 2 Jul 2020, Xunlei Pang wrote:
> This patch introduces two counters to maintain the actual number
> of partial objects dynamically instead of iterating the partial
> page lists with list_lock held.
>
> New counters of kmem_cache_node are: pfree_objects, ptotal_objects.
> The main operations are under list_lock in slow path, its performance
> impact is minimal.
If at all then these counters need to be under CONFIG_SLUB_DEBUG.
> --- a/mm/slab.h
> +++ b/mm/slab.h
> @@ -616,6 +616,8 @@ struct kmem_cache_node {
> #ifdef CONFIG_SLUB
> unsigned long nr_partial;
> struct list_head partial;
> + atomic_long_t pfree_objects; /* partial free objects */
> + atomic_long_t ptotal_objects; /* partial total objects */
Please in the CONFIG_SLUB_DEBUG. Without CONFIG_SLUB_DEBUG we need to
build with minimal memory footprint.
> #ifdef CONFIG_SLUB_DEBUG
> atomic_long_t nr_slabs;
> atomic_long_t total_objects;
> diff --git a/mm/slub.c b/mm/slub.c
Also this looks to be quite heavy on the cache and on execution time. Note
that the list_lock could be taken frequently in the performance sensitive
case of freeing an object that is not in the partial lists.
next prev parent reply other threads:[~2020-07-07 6:59 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-02 8:32 [PATCH 1/2] mm/slub: Introduce two counters for the partial objects Xunlei Pang
2020-07-02 8:32 ` [PATCH 2/2] mm/slub: Get rid of count_partial() Xunlei Pang
2020-07-02 11:59 ` [PATCH 1/2] mm/slub: Introduce two counters for the partial objects Pekka Enberg
2020-07-03 9:37 ` xunlei
2020-07-07 15:23 ` Pekka Enberg
2020-07-09 14:32 ` Christopher Lameter
2020-07-31 2:57 ` xunlei
2020-07-07 6:59 ` Christopher Lameter [this message]
2020-07-31 2:52 ` xunlei
2020-08-06 12:42 ` Vlastimil Babka
2020-08-07 7:25 ` Pekka Enberg
2020-08-07 13:02 ` Christopher Lameter
2020-08-07 17:28 ` Pekka Enberg
2020-08-10 11:56 ` xunlei
2020-08-11 12:52 ` Christopher Lameter
2020-08-20 13:58 ` Pekka Enberg
2020-08-24 9:59 ` xunlei
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