From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kent Overstreet Subject: [PATCH 6/9] mtip32xx: handle arbitrary size bios Date: Mon, 4 Nov 2013 15:36:24 -0800 Message-ID: <1383608187-27368-7-git-send-email-kmo@daterainc.com> References: <1383608187-27368-1-git-send-email-kmo@daterainc.com> Cc: axboe@kernel.dk, hch@infradead.org, Kent Overstreet To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-btrfs@vger.kernel.org Return-path: Received: from mail-pd0-f181.google.com ([209.85.192.181]:59923 "EHLO mail-pd0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754009Ab3KDXgu (ORCPT ); Mon, 4 Nov 2013 18:36:50 -0500 Received: by mail-pd0-f181.google.com with SMTP id x10so7284715pdj.26 for ; Mon, 04 Nov 2013 15:36:48 -0800 (PST) In-Reply-To: <1383608187-27368-1-git-send-email-kmo@daterainc.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: We get a measurable performance increase by handling this in the driver when we're already looping over the biovec, instead of handling it separately in generic_make_request() (or bio_add_page() originally) Signed-off-by: Kent Overstreet --- drivers/block/mtip32xx/mtip32xx.c | 46 +++++++++++++-------------------------- 1 file changed, 15 insertions(+), 31 deletions(-) diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c index d4c669b..c5a7a96 100644 --- a/drivers/block/mtip32xx/mtip32xx.c +++ b/drivers/block/mtip32xx/mtip32xx.c @@ -2648,24 +2648,6 @@ static void mtip_hw_submit_io(struct driver_data *dd, sector_t sector, } /* - * Release a command slot. - * - * @dd Pointer to the driver data structure. - * @tag Slot tag - * - * return value - * None - */ -static void mtip_hw_release_scatterlist(struct driver_data *dd, int tag, - int unaligned) -{ - struct semaphore *sem = unaligned ? &dd->port->cmd_slot_unal : - &dd->port->cmd_slot; - release_slot(dd->port, tag); - up(sem); -} - -/* * Obtain a command slot and return its associated scatter list. * * @dd Pointer to the driver data structure. @@ -4016,21 +3998,22 @@ static void mtip_make_request(struct request_queue *queue, struct bio *bio) sg = mtip_hw_get_scatterlist(dd, &tag, unaligned); if (likely(sg != NULL)) { - if (unlikely((bio)->bi_vcnt > MTIP_MAX_SG)) { - dev_warn(&dd->pdev->dev, - "Maximum number of SGL entries exceeded\n"); - bio_io_error(bio); - mtip_hw_release_scatterlist(dd, tag, unaligned); - return; - } - /* Create the scatter list for this bio. */ bio_for_each_segment(bvec, bio, iter) { - sg_set_page(&sg[nents], - bvec.bv_page, - bvec.bv_len, - bvec.bv_offset); - nents++; + if (unlikely(nents == MTIP_MAX_SG)) { + struct bio *split = bio_clone(bio, GFP_NOIO); + + split->bi_iter = iter; + bio->bi_iter.bi_size -= iter.bi_size; + bio_chain(split, bio); + generic_make_request(split); + break; + } + + sg_set_page(&sg[nents++], + bvec.bv_page, + bvec.bv_len, + bvec.bv_offset); } /* Issue the read/write. */ @@ -4145,6 +4128,7 @@ skip_create_disk: blk_queue_max_hw_sectors(dd->queue, 0xffff); blk_queue_max_segment_size(dd->queue, 0x400000); blk_queue_io_min(dd->queue, 4096); + set_bit(QUEUE_FLAG_LARGEBIOS, &dd->queue->queue_flags); /* * write back cache is not supported in the device. FUA depends on -- 1.8.4.rc3