The patch titled dio: use a slab cache for struct dio has been added to the -mm tree. Its filename is dio-use-a-slab-cache-for-struct-dio.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: dio: use a slab cache for struct dio From: Andi Kleen <ak@xxxxxxxxxxxxxxx> A direct slab call is slightly faster than kmalloc and can be better cached per CPU. It also avoids rounding to the next kmalloc slab. In addition this enforces cache line alignment for struct dio to avoid any false sharing. Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx> Acked-by: Jeff Moyer <jmoyer@xxxxxxxxxx> Cc: Jens Axboe <axboe@xxxxxxxxx> Cc: Christoph Hellwig <hch@xxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/direct-io.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff -puN fs/direct-io.c~dio-use-a-slab-cache-for-struct-dio fs/direct-io.c --- a/fs/direct-io.c~dio-use-a-slab-cache-for-struct-dio +++ a/fs/direct-io.c @@ -140,7 +140,9 @@ struct dio { * wish that they not be zeroed. */ struct page *pages[DIO_PAGES]; /* page buffer */ -}; +} ____cacheline_aligned_in_smp; + +static struct kmem_cache *dio_cache __read_mostly; static void __inode_dio_wait(struct inode *inode) { @@ -330,7 +332,7 @@ static void dio_bio_end_aio(struct bio * if (remaining == 0) { dio_complete(dio, dio->iocb->ki_pos, 0, true); - kfree(dio); + kmem_cache_free(dio_cache, dio); } } @@ -1178,7 +1180,7 @@ direct_io_worker(int rw, struct kiocb *i if (ret2 == 0) { ret = dio_complete(dio, offset, ret, false); - kfree(dio); + kmem_cache_free(dio_cache, dio); } else BUG_ON(ret != -EIOCBQUEUED); @@ -1254,7 +1256,7 @@ __blockdev_direct_IO(int rw, struct kioc if (rw == READ && end == offset) return 0; - dio = kmalloc(sizeof(*dio), GFP_KERNEL); + dio = kmem_cache_alloc(dio_cache, GFP_KERNEL); retval = -ENOMEM; if (!dio) goto out; @@ -1278,7 +1280,7 @@ __blockdev_direct_IO(int rw, struct kioc end - 1); if (retval) { mutex_unlock(&inode->i_mutex); - kfree(dio); + kmem_cache_free(dio_cache, dio); goto out; } } @@ -1306,3 +1308,10 @@ out: return retval; } EXPORT_SYMBOL(__blockdev_direct_IO); + +static __init int dio_init(void) +{ + dio_cache = KMEM_CACHE(dio, SLAB_PANIC); + return 0; +} +module_init(dio_init) _ Patches currently in -mm which might be from ak@xxxxxxxxxxxxxxx are linux-next.patch dio-separate-fields-only-used-in-the-submission-path-from-struct-dio.patch dio-separate-fields-only-used-in-the-submission-path-from-struct-dio-checkpatch-fixes.patch dio-fix-a-wrong-comment.patch dio-rearrange-fields-in-dio-dio_submit-to-avoid-holes.patch dio-use-a-slab-cache-for-struct-dio.patch dio-separate-map_bh-from-dio-v2.patch dio-inline-the-complete-submission-path-v2.patch dio-merge-direct_io_walker-into-__blockdev_direct_io.patch dio-remove-unnecessary-dio-argument-from-dio_pages_present.patch dio-remove-unused-dio-parameter-from-dio_bio_add_page.patch vfs-cache-request_queue-in-struct-block_device.patch dio-optimize-cache-misses-in-the-submission-path-v2.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