From: David Rientjes <rientjes@google.com>
To: Aaron Lu <aaron.lu@intel.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Huang Ying <ying.huang@intel.com>,
Dave Hansen <dave.hansen@intel.com>,
Kemi Wang <kemi.wang@intel.com>,
Tim Chen <tim.c.chen@linux.intel.com>,
Andi Kleen <ak@linux.intel.com>, Michal Hocko <mhocko@suse.com>,
Vlastimil Babka <vbabka@suse.cz>,
Mel Gorman <mgorman@techsingularity.net>,
Matthew Wilcox <willy@infradead.org>
Subject: Re: [PATCH v3 2/3] mm/free_pcppages_bulk: do not hold lock when picking pages to free
Date: Mon, 26 Feb 2018 13:53:10 -0800 (PST) [thread overview]
Message-ID: <alpine.DEB.2.20.1802261352160.135844@chino.kir.corp.google.com> (raw)
In-Reply-To: <20180226135346.7208-3-aaron.lu@intel.com>
On Mon, 26 Feb 2018, Aaron Lu wrote:
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 3154859cccd6..35576da0a6c9 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -1116,13 +1116,11 @@ static void free_pcppages_bulk(struct zone *zone, int count,
> int migratetype = 0;
> int batch_free = 0;
> bool isolated_pageblocks;
> + struct page *page, *tmp;
> + LIST_HEAD(head);
>
> pcp->count -= count;
> - spin_lock(&zone->lock);
> - isolated_pageblocks = has_isolate_pageblock(zone);
> -
> while (count) {
> - struct page *page;
> struct list_head *list;
>
> /*
> @@ -1144,26 +1142,31 @@ static void free_pcppages_bulk(struct zone *zone, int count,
> batch_free = count;
>
> do {
> - int mt; /* migratetype of the to-be-freed page */
> -
> page = list_last_entry(list, struct page, lru);
> /* must delete as __free_one_page list manipulates */
Looks good in general, but I'm not sure how I reconcile this comment with
the new implementation that later links page->lru again.
> list_del(&page->lru);
>
> - mt = get_pcppage_migratetype(page);
> - /* MIGRATE_ISOLATE page should not go to pcplists */
> - VM_BUG_ON_PAGE(is_migrate_isolate(mt), page);
> - /* Pageblock could have been isolated meanwhile */
> - if (unlikely(isolated_pageblocks))
> - mt = get_pageblock_migratetype(page);
> -
> if (bulkfree_pcp_prepare(page))
> continue;
>
> - __free_one_page(page, page_to_pfn(page), zone, 0, mt);
> - trace_mm_page_pcpu_drain(page, 0, mt);
> + list_add_tail(&page->lru, &head);
> } while (--count && --batch_free && !list_empty(list));
> }
> +
> + spin_lock(&zone->lock);
> + isolated_pageblocks = has_isolate_pageblock(zone);
> +
> + list_for_each_entry_safe(page, tmp, &head, lru) {
> + int mt = get_pcppage_migratetype(page);
> + /* MIGRATE_ISOLATE page should not go to pcplists */
> + VM_BUG_ON_PAGE(is_migrate_isolate(mt), page);
> + /* Pageblock could have been isolated meanwhile */
> + if (unlikely(isolated_pageblocks))
> + mt = get_pageblock_migratetype(page);
> +
> + __free_one_page(page, page_to_pfn(page), zone, 0, mt);
> + trace_mm_page_pcpu_drain(page, 0, mt);
> + }
> spin_unlock(&zone->lock);
> }
>
next prev parent reply other threads:[~2018-02-26 21:53 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-26 13:53 [PATCH v3 0/3] mm: improve zone->lock scalability Aaron Lu
2018-02-26 13:53 ` [PATCH v3 1/3] mm/free_pcppages_bulk: update pcp->count inside Aaron Lu
2018-02-26 21:48 ` David Rientjes
2018-02-27 1:56 ` Aaron Lu
2018-02-27 3:12 ` Aaron Lu
2018-02-26 13:53 ` [PATCH v3 2/3] mm/free_pcppages_bulk: do not hold lock when picking pages to free Aaron Lu
2018-02-26 21:53 ` David Rientjes [this message]
2018-02-27 2:00 ` Aaron Lu
2018-02-27 3:17 ` Aaron Lu
2018-02-26 13:53 ` [PATCH v3 3/3] mm/free_pcppages_bulk: prefetch buddy while not holding lock Aaron Lu
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