lkml.org 
[lkml]   [2008]   [Oct]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH, RFC, v2] shmat: introduce flag SHM_MAP_HINT
    On Tue, Oct 07, 2008 at 10:20:30AM +0200, Andi Kleen wrote:
    > On Tue, Oct 07, 2008 at 09:57:50AM +0300, Kirill A. Shutemov wrote:
    > > It allows interpret attach address as a hint, not as exact address.
    >
    > Please expand the description a bit. Rationale. etc.
    >
    > > @@ -55,6 +55,7 @@ struct shmid_ds {
    > > #define SHM_RND 020000 /* round attach address to SHMLBA boundary */
    > > #define SHM_REMAP 040000 /* take-over region on attach */
    > > #define SHM_EXEC 0100000 /* execution access */
    > > +#define SHM_MAP_HINT 0200000 /* interpret attach address as a hint */
    >
    > search hint

    Ok.

    > > @@ -892,7 +892,7 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
    > > sfd->vm_ops = NULL;
    > >
    > > down_write(&current->mm->mmap_sem);
    > > - if (addr && !(shmflg & SHM_REMAP)) {
    > > + if (addr && !(shmflg & (SHM_REMAP|SHM_MAP_HINT))) {
    >
    > I think you were right earlier that it can be just deleted, so why don't
    > you just do that?

    I want say that we shouldn't do this check if shmaddr is a search hint.
    I'm not sure that check is unneeded if shmadd is the exact address.

    --
    Regards, Kirill A. Shutemov
    + Belarus, Minsk
    + ALT Linux Team, http://www.altlinux.com/
    [unhandled content-type:application/pgp-signature]
    \
     
     \ /
      Last update: 2008-10-07 12:11    [W:0.201 / U:0.356 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site