From: Vlastimil Babka <vbabka@suse.cz>
To: Mel Gorman <mgorman@techsingularity.net>,
Andrew Morton <akpm@linux-foundation.org>
Cc: Aaron Lu <aaron.lu@intel.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Michal Hocko <mhocko@kernel.org>,
Jesper Dangaard Brouer <brouer@redhat.com>,
LKML <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>
Subject: Re: [PATCH 4/6] mm/page_alloc: Drain the requested list first during bulk free
Date: Thu, 17 Feb 2022 10:42:09 +0100 [thread overview]
Message-ID: <25381c82-36b6-e62b-de20-db438bc85adb@suse.cz> (raw)
In-Reply-To: <20220217002227.5739-5-mgorman@techsingularity.net>
On 2/17/22 01:22, Mel Gorman wrote:
> Prior to the series, pindex 0 (order-0 MIGRATE_UNMOVABLE) was always
> skipped first and the precise reason is forgotten. A potential reason may
> have been to artificially preserve MIGRATE_UNMOVABLE but there is no reason
> why that would be optimal as it depends on the workload. The more likely
> reason is that it was less complicated to do a pre-increment instead of
> a post-increment in terms of overall code flow. As free_pcppages_bulk()
> now typically receives the pindex of the PCP list that exceeded high,
> always start draining that list.
>
> Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
> ---
> mm/page_alloc.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index dfc347a58ea6..635a4e0f70b4 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -1463,6 +1463,10 @@ static void free_pcppages_bulk(struct zone *zone, int count,
> * below while (list_empty(list)) loop.
> */
> count = min(pcp->count, count);
> +
> + /* Ensure requested pindex is drained first. */
> + pindex = pindex - 1;
> +
> while (count > 0) {
> struct list_head *list;
> int nr_pages;
next prev parent reply other threads:[~2022-02-17 9:42 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-17 0:22 [PATCH v2 0/6] Follow-up on high-order PCP caching Mel Gorman
2022-02-17 0:22 ` [PATCH 1/6] mm/page_alloc: Fetch the correct pcp buddy during bulk free Mel Gorman
2022-02-17 1:43 ` Aaron Lu
2022-02-17 0:22 ` [PATCH 2/6] mm/page_alloc: Track range of active PCP lists " Mel Gorman
2022-02-17 9:41 ` Vlastimil Babka
2022-02-17 0:22 ` [PATCH 3/6] mm/page_alloc: Simplify how many pages are selected per pcp list " Mel Gorman
2022-02-17 0:22 ` [PATCH 4/6] mm/page_alloc: Drain the requested list first " Mel Gorman
2022-02-17 9:42 ` Vlastimil Babka [this message]
2022-02-17 0:22 ` [PATCH 5/6] mm/page_alloc: Free pages in a single pass " Mel Gorman
2022-02-17 1:53 ` Aaron Lu
2022-02-17 8:49 ` Aaron Lu
2022-02-17 9:31 ` Mel Gorman
2022-02-18 4:20 ` Aaron Lu
2022-02-18 9:20 ` Mel Gorman
2022-02-21 13:38 ` Aaron Lu
2022-02-23 11:30 ` Aaron Lu
2022-02-23 13:05 ` Mel Gorman
2022-02-24 1:34 ` Lu, Aaron
2022-02-18 6:07 ` Aaron Lu
2022-02-18 9:47 ` Mel Gorman
2022-02-18 12:13 ` Aaron Lu
2022-02-17 0:22 ` [PATCH 6/6] mm/page_alloc: Limit number of high-order pages on PCP " Mel Gorman
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