lkml.org 
[lkml]   [2012]   [Jul]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    SubjectRe: [PATCH 3/3] mm: fix return value in __alloc_contig_migrate_range()
    Date
    Joonsoo Kim <js1304@gmail.com> writes:

    > migrate_pages() would return positive value in some failure case,
    > so 'ret > 0 ? 0 : ret' may be wrong.
    > This fix it and remove one dead statement.
    >
    > Signed-off-by: Joonsoo Kim <js1304@gmail.com>
    > Cc: Michal Nazarewicz <mina86@mina86.com>
    > Cc: Marek Szyprowski <m.szyprowski@samsung.com>
    > Cc: Minchan Kim <minchan@kernel.org>
    > Cc: Christoph Lameter <cl@linux.com>

    Have you actually encountered this problem? If migrate_pages() fails
    with a positive value, the code that you are removing kicks in and
    -EBUSY is assigned to ret (now that I look at it, I think that in the
    current code the "return ret > 0 ? 0 : ret;" statement could be reduced
    to "return ret;"). Your code seems to be cleaner, but the commit
    message does not look accurate to me.

    > diff --git a/mm/page_alloc.c b/mm/page_alloc.c
    > index 4403009..02d4519 100644
    > --- a/mm/page_alloc.c
    > +++ b/mm/page_alloc.c
    > @@ -5673,7 +5673,6 @@ static int __alloc_contig_migrate_range(unsigned long start, unsigned long end)
    > }
    > tries = 0;
    > } else if (++tries == 5) {
    > - ret = ret < 0 ? ret : -EBUSY;
    > break;
    > }
    >
    > @@ -5683,7 +5682,7 @@ static int __alloc_contig_migrate_range(unsigned long start, unsigned long end)
    > }
    >
    > putback_lru_pages(&cc.migratepages);
    > - return ret > 0 ? 0 : ret;
    > + return ret <= 0 ? ret : -EBUSY;
    > }
    >
    > /*

    --
    Best regards, _ _
    .o. | Liege of Serenly Enlightened Majesty of o' \,=./ `o
    ..o | Computer Science, Michal "mina86" Nazarewicz (o o)
    ooo +-<mina86-mina86.com>-<jid:mina86-jabber.org>--ooO--(_)--Ooo--
    [unhandled content-type:application/pgp-signature]
    \
     
     \ /
      Last update: 2012-07-16 20:21    [W:0.025 / U:0.760 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site