From: Vlastimil Babka <vbabka@suse.cz>
To: Oscar Salvador <osalvador@suse.de>,
Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@redhat.com>,
Michal Hocko <mhocko@kernel.org>,
Muchun Song <songmuchun@bytedance.com>,
Mike Kravetz <mike.kravetz@oracle.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 1/4] mm,page_alloc: Bail out earlier on -ENOMEM in alloc_contig_migrate_range
Date: Mon, 15 Mar 2021 12:00:41 +0100 [thread overview]
Message-ID: <bd60e2e2-3683-69a4-a922-20a446bac61f@suse.cz> (raw)
In-Reply-To: <20210310150853.13541-2-osalvador@suse.de>
On 3/10/21 4:08 PM, Oscar Salvador wrote:
> Currently, __alloc_contig_migrate_range can generate -EINTR, -ENOMEM or -EBUSY,
> and report them down the chain.
> The problem is that when migrate_pages() reports -ENOMEM, we keep going till we
> exhaust all the try-attempts (5 at the moment) instead of bailing out.
>
> migrate_pages bails out right away on -ENOMEM because it is considered a fatal
> error. Do the same here instead of keep going and retrying.
>
> Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
> ---
> mm/page_alloc.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 3e4b29ee2b1e..94467f1b85ff 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -8484,7 +8484,7 @@ static int __alloc_contig_migrate_range(struct compact_control *cc,
> }
> tries = 0;
> } else if (++tries == 5) {
> - ret = ret < 0 ? ret : -EBUSY;
> + ret = -EBUSY;
> break;
> }
>
> @@ -8494,6 +8494,12 @@ static int __alloc_contig_migrate_range(struct compact_control *cc,
>
> ret = migrate_pages(&cc->migratepages, alloc_migration_target,
> NULL, (unsigned long)&mtc, cc->mode, MR_CONTIG_RANGE);
> + /*
> + * On -ENOMEM, migrate_pages() bails out right away. It is pointless
> + * to retry again over this error, so do the same here.
> + */
> + if (ret == -ENOMEM)
> + break;
> }
> if (ret < 0) {
> putback_movable_pages(&cc->migratepages);
>
next prev parent reply other threads:[~2021-03-15 11:01 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-10 15:08 [PATCH v4 0/4] Make alloc_contig_range handle Hugetlb pages Oscar Salvador
2021-03-10 15:08 ` [PATCH v4 1/4] mm,page_alloc: Bail out earlier on -ENOMEM in alloc_contig_migrate_range Oscar Salvador
2021-03-15 11:00 ` Vlastimil Babka [this message]
2021-03-15 11:10 ` David Hildenbrand
2021-03-10 15:08 ` [PATCH v4 2/4] mm,compaction: Let isolate_migratepages_{range,block} return error codes Oscar Salvador
2021-03-15 11:03 ` Vlastimil Babka
2021-03-10 15:08 ` [PATCH v4 3/4] mm: Make alloc_contig_range handle free hugetlb pages Oscar Salvador
2021-03-10 15:08 ` [PATCH v4 4/4] mm: Make alloc_contig_range handle in-use " Oscar Salvador
2021-03-15 9:06 ` [PATCH v4 0/4] Make alloc_contig_range handle Hugetlb pages David Hildenbrand
2021-03-15 10:27 ` Oscar Salvador
2021-03-15 10:28 ` David Hildenbrand
2021-03-17 9:43 ` Oscar Salvador
2021-03-17 9:48 ` David Hildenbrand
2021-03-17 10:05 ` Oscar Salvador
2021-03-17 10:06 ` Oscar Salvador
2021-03-17 10:07 ` David Hildenbrand
2021-03-15 10:23 ` Oscar Salvador
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