Well, then you can still do the one-time allocation for that CPU slot,
and re-check the CPU number after vmalloc() returns. If it is different
(or always, for that matter) then you jump back to the "is the array for
this CPU allocated" check until the array _is_ allocated for that CPU
and you don't need to allocate it (so you won't sleep). At most you
will need to loop once for each available CPU if you are unlucky enough
to be rescheduled to a different CPU after each call to vmalloc().
Like:
int cpunum = this_cpu();
char *newbuf = NULL;
while (unlikely(NTFS_SB(sb)->s_compr_array[cpunum] == NULL)) {
newbuf = vmalloc(NTFS_DECOMPR_BUFFER_SIZE);
/* Re-check the buffer case we slept in vmalloc() and
* someone else already allocated a buffer for "this" CPU.
*/
if (likely(NTFS_SB(sb)->s_compr_array[cpunum] == NULL)) {
NTFS_SB(sb)->s_compr_array[cpunum] = newbuf;
newbuf = NULL;
}
cpunum = this_cpu();
}
/* Hmm, we slept in vmalloc and we don't need the new buffer */
if (unlikely(newbuf != NULL))
vfree(newbuf);
> >3) Any allocated buffers are freed in the same manner they are now -
> > when the last compressed volume is unmounted. There may be some or
> > all entries that are still NULL.
> >
> >This also avoids allocating buffers when there are no files which are
> >actually compressed.
>
> True it does, but unfortunately it doesn't work. )-:
Now it does... ;-).
Cheers, Andreas
-- Andreas Dilger http://www-mddsp.enel.ucalgary.ca/People/adilger/ http://sourceforge.net/projects/ext2resize/- 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/