• Tejun Heo's avatar
    mempool: fix first round failure behavior · 1ebb7044
    Tejun Heo authored
    mempool modifies gfp_mask so that the backing allocator doesn't try too
    hard or trigger warning message when there's pool to fall back on.  In
    addition, for the first try, it removes __GFP_WAIT and IO, so that it
    doesn't trigger reclaim or wait when allocation can be fulfilled from
    pool; however, when that allocation fails and pool is empty too, it waits
    for the pool to be replenished before retrying.
    
    Allocation which could have succeeded after a bit of reclaim has to wait
    on the reserved items and it's not like mempool doesn't retry with
    __GFP_WAIT and IO.  It just does that *after* someone returns an element,
    pointlessly delaying things.
    
    Fix it by retrying immediately if the first round of allocation attempts
    w/o __GFP_WAIT and IO fails.
    
    [akpm@linux-foundation.org: shorten the lock hold time]
    Signed-off-by: default avatarTejun Heo <tj@kernel.org>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    1ebb7044
mempool.c 10.4 KB