linux-kernel - Re: [PATCH v7 1/7] mm,page_alloc: Bail out earlier on -ENOMEM in alloc_contig_migrate

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Message-ID: <fca31c2f-4cde-8329-f302-1cf005087bc0@oracle.com>
Date:   Tue, 13 Apr 2021 10:00:33 -0700
From:   Mike Kravetz <mike.kravetz@...cle.com>
To:     Oscar Salvador <osalvador@...e.de>,
        Andrew Morton <akpm@...ux-foundation.org>
Cc:     Vlastimil Babka <vbabka@...e.cz>,
        David Hildenbrand <david@...hat.com>,
        Michal Hocko <mhocko@...nel.org>,
        Muchun Song <songmuchun@...edance.com>, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v7 1/7] mm,page_alloc: Bail out earlier on -ENOMEM in
 alloc_contig_migrate_range

On 4/13/21 3:47 AM, 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.
> Note that this is not fixing a real issue, just a cosmetic change. Although we
> can save some cycles by backing off ealier
> 
> Signed-off-by: Oscar Salvador <osalvador@...e.de>
> Acked-by: Vlastimil Babka <vbabka@...e.cz>
> Reviewed-by: David Hildenbrand <david@...hat.com>
> Acked-by: Michal Hocko <mhocko@...e.com>

Acked-by: Mike Kravetz <mike.kravetz@...cle.com>

-- 
Mike Kravetz