The patch titled Subject: mempool: fix first round failure behavior has been removed from the -mm tree. Its filename was mempool-fix-first-round-failure-behavior.patch This patch was dropped because it was merged into mainline or a subsystem tree The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ From: Tejun Heo <tj@xxxxxxxxxx> Subject: mempool: fix first round failure behavior 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@xxxxxxxxxxxxxxxxxxxx: shorten the lock hold time] Signed-off-by: Tejun Heo <tj@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/mempool.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff -puN mm/mempool.c~mempool-fix-first-round-failure-behavior mm/mempool.c --- a/mm/mempool.c~mempool-fix-first-round-failure-behavior +++ a/mm/mempool.c @@ -221,14 +221,23 @@ repeat_alloc: return element; } - /* We must not sleep in the GFP_ATOMIC case */ + /* + * We use gfp mask w/o __GFP_WAIT or IO for the first round. If + * alloc failed with that and @pool was empty, retry immediately. + */ + if (gfp_temp != gfp_mask) { + spin_unlock_irqrestore(&pool->lock, flags); + gfp_temp = gfp_mask; + goto repeat_alloc; + } + + /* We must not sleep if !__GFP_WAIT */ if (!(gfp_mask & __GFP_WAIT)) { spin_unlock_irqrestore(&pool->lock, flags); return NULL; } /* Let's wait for someone else to return an element to @pool */ - gfp_temp = gfp_mask; init_wait(&wait); prepare_to_wait(&pool->wait, &wait, TASK_UNINTERRUPTIBLE); _ Patches currently in -mm which might be from tj@xxxxxxxxxx are origin.patch linux-next.patch sysctl-add-the-kernelns_last_pid-control.patch scatterlist-new-helper-functions.patch scatterlist-new-helper-functions-update.patch scatterlist-new-helper-functions-update-fix.patch c-r-introduce-checkpoint_restore-symbol.patch c-r-procfs-add-start_data-end_data-start_brk-members-to-proc-pid-stat-v4.patch c-r-procfs-add-start_data-end_data-start_brk-members-to-proc-pid-stat-v4-fix.patch c-r-prctl-add-pr_set_mm-codes-to-set-up-mm_struct-entries.patch c-r-prctl-add-pr_set_mm-codes-to-set-up-mm_struct-entries-fix.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html