lkml.org 
[lkml]   [2007]   [Apr]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: can a kmalloc be both GFP_ATOMIC and GFP_KERNEL at the same time?
    On Mon, 30 Apr 2007 04:46:54 -0400 (EDT) "Robert P. J. Day" <rpjday@mindspring.com> wrote:

    > On Mon, 30 Apr 2007, Andrew Morton wrote:
    >
    > > On Sat, 28 Apr 2007 09:40:39 -0400 (EDT) "Robert P. J. Day" <rpjday@mindspring.com> wrote:
    > >
    > > >
    > > > i'd always assumed that the type flags of GFP_ATOMIC and GFP_KERNEL
    > > > were mutually exclusive when it came to calling kmalloc(), at least
    > > > based on everything i'd read. so i'm not sure how to interpret the
    > > > following:
    > > >
    > > > drivers/scsi/aic7xxx_old.c: aic_dev = kmalloc(sizeof(struct aic_dev_data), GFP_ATOMIC | GFP_KERNEL);
    > > > drivers/message/i2o/device.c: resblk = kmalloc(buflen + 8, GFP_KERNEL | GFP_ATOMIC);
    > > >
    > > > clarification?
    > >
    > > GFP_ATOMIC implies that the memory comes from the zones which
    > > GFP_KERNEL also uses. So the above usage of GFP_KERNEL is redundant
    > > and should be removed.
    >
    > hang on ... based on an email i just got, is that reference to
    > GFP_KERNEL "redundant" or "conflicting"? big difference there. and
    > is the proper fix to remove "GFP_KERNEL" in both cases?
    >

    umm, yeah, oops. GFP_KERNEL|GFP_ATOMIC is not a redundant combination.
    It's GFP_KERNEL plus "is able to access emergency pools". We'd normally
    represent that as GFP_KERNEL|__GFP_HIGH.

    However it's questionable whether that was the intent in those two drivers.
    `git-blame' might tell.

    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2007-04-30 19:05    [W:3.160 / U:0.680 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site