Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758698AbYBGJVO (ORCPT ); Thu, 7 Feb 2008 04:21:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754908AbYBGJUK (ORCPT ); Thu, 7 Feb 2008 04:20:10 -0500 Received: from brick.kernel.dk ([87.55.233.238]:18479 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753123AbYBGJUB (ORCPT ); Thu, 7 Feb 2008 04:20:01 -0500 From: Jens Axboe To: linux-kernel@vger.kernel.org Cc: Alan.Brunelle@hp.com, arjan@linux.intel.com, dgc@sgi.com, npiggin@suse.de, Jens Axboe Subject: [PATCH 1/8] block: split softirq handling into blk-softirq.c Date: Thu, 7 Feb 2008 10:18:58 +0100 Message-Id: <1202375945-29525-2-git-send-email-jens.axboe@oracle.com> X-Mailer: git-send-email 1.5.4.22.g7a20 In-Reply-To: <1202375945-29525-1-git-send-email-jens.axboe@oracle.com> References: <1202375945-29525-1-git-send-email-jens.axboe@oracle.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7335 Lines: 266 Signed-off-by: Jens Axboe --- block/Makefile | 3 +- block/blk-core.c | 88 ------------------------------------------- block/blk-softirq.c | 103 +++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 105 insertions(+), 89 deletions(-) create mode 100644 block/blk-softirq.c diff --git a/block/Makefile b/block/Makefile index 5a43c7d..b064190 100644 --- a/block/Makefile +++ b/block/Makefile @@ -4,7 +4,8 @@ obj-$(CONFIG_BLOCK) := elevator.o blk-core.o blk-tag.o blk-sysfs.o \ blk-barrier.o blk-settings.o blk-ioc.o blk-map.o \ - blk-exec.o blk-merge.o ioctl.o genhd.o scsi_ioctl.o + blk-exec.o blk-merge.o blk-softirq.o ioctl.o genhd.o \ + scsi_ioctl.o obj-$(CONFIG_BLK_DEV_BSG) += bsg.o obj-$(CONFIG_IOSCHED_NOOP) += noop-iosched.o diff --git a/block/blk-core.c b/block/blk-core.c index 4afb39c..11d79f6 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -26,8 +26,6 @@ #include #include #include -#include -#include #include #include @@ -50,8 +48,6 @@ struct kmem_cache *blk_requestq_cachep; */ static struct workqueue_struct *kblockd_workqueue; -static DEFINE_PER_CPU(struct list_head, blk_cpu_done); - static void drive_stat_acct(struct request *rq, int new_io) { int rw = rq_data_dir(rq); @@ -1605,82 +1601,6 @@ static int __end_that_request_first(struct request *req, int error, } /* - * splice the completion data to a local structure and hand off to - * process_completion_queue() to complete the requests - */ -static void blk_done_softirq(struct softirq_action *h) -{ - struct list_head *cpu_list, local_list; - - local_irq_disable(); - cpu_list = &__get_cpu_var(blk_cpu_done); - list_replace_init(cpu_list, &local_list); - local_irq_enable(); - - while (!list_empty(&local_list)) { - struct request *rq; - - rq = list_entry(local_list.next, struct request, donelist); - list_del_init(&rq->donelist); - rq->q->softirq_done_fn(rq); - } -} - -static int __cpuinit blk_cpu_notify(struct notifier_block *self, - unsigned long action, void *hcpu) -{ - /* - * If a CPU goes away, splice its entries to the current CPU - * and trigger a run of the softirq - */ - if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) { - int cpu = (unsigned long) hcpu; - - local_irq_disable(); - list_splice_init(&per_cpu(blk_cpu_done, cpu), - &__get_cpu_var(blk_cpu_done)); - raise_softirq_irqoff(BLOCK_SOFTIRQ); - local_irq_enable(); - } - - return NOTIFY_OK; -} - - -static struct notifier_block blk_cpu_notifier __cpuinitdata = { - .notifier_call = blk_cpu_notify, -}; - -/** - * blk_complete_request - end I/O on a request - * @req: the request being processed - * - * Description: - * Ends all I/O on a request. It does not handle partial completions, - * unless the driver actually implements this in its completion callback - * through requeueing. The actual completion happens out-of-order, - * through a softirq handler. The user must have registered a completion - * callback through blk_queue_softirq_done(). - **/ - -void blk_complete_request(struct request *req) -{ - struct list_head *cpu_list; - unsigned long flags; - - BUG_ON(!req->q->softirq_done_fn); - - local_irq_save(flags); - - cpu_list = &__get_cpu_var(blk_cpu_done); - list_add_tail(&req->donelist, cpu_list); - raise_softirq_irqoff(BLOCK_SOFTIRQ); - - local_irq_restore(flags); -} -EXPORT_SYMBOL(blk_complete_request); - -/* * queue lock must be held */ static void end_that_request_last(struct request *req, int error) @@ -2004,8 +1924,6 @@ EXPORT_SYMBOL(kblockd_flush_work); int __init blk_dev_init(void) { - int i; - kblockd_workqueue = create_workqueue("kblockd"); if (!kblockd_workqueue) panic("Failed to create kblockd\n"); @@ -2016,12 +1934,6 @@ int __init blk_dev_init(void) blk_requestq_cachep = kmem_cache_create("blkdev_queue", sizeof(struct request_queue), 0, SLAB_PANIC, NULL); - for_each_possible_cpu(i) - INIT_LIST_HEAD(&per_cpu(blk_cpu_done, i)); - - open_softirq(BLOCK_SOFTIRQ, blk_done_softirq, NULL); - register_hotcpu_notifier(&blk_cpu_notifier); - return 0; } diff --git a/block/blk-softirq.c b/block/blk-softirq.c new file mode 100644 index 0000000..05f9451 --- /dev/null +++ b/block/blk-softirq.c @@ -0,0 +1,103 @@ +/* + * Functions related to softirq rq completions + */ +#include +#include +#include +#include +#include +#include +#include + +#include "blk.h" + +static DEFINE_PER_CPU(struct list_head, blk_cpu_done); + +static int __cpuinit blk_cpu_notify(struct notifier_block *self, + unsigned long action, void *hcpu) +{ + /* + * If a CPU goes away, splice its entries to the current CPU + * and trigger a run of the softirq + */ + if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) { + int cpu = (unsigned long) hcpu; + + local_irq_disable(); + list_splice_init(&per_cpu(blk_cpu_done, cpu), + &__get_cpu_var(blk_cpu_done)); + raise_softirq_irqoff(BLOCK_SOFTIRQ); + local_irq_enable(); + } + + return NOTIFY_OK; +} + + +static struct notifier_block blk_cpu_notifier __cpuinitdata = { + .notifier_call = blk_cpu_notify, +}; + +/* + * splice the completion data to a local structure and hand off to + * process_completion_queue() to complete the requests + */ +static void blk_done_softirq(struct softirq_action *h) +{ + struct list_head *cpu_list, local_list; + + local_irq_disable(); + cpu_list = &__get_cpu_var(blk_cpu_done); + list_replace_init(cpu_list, &local_list); + local_irq_enable(); + + while (!list_empty(&local_list)) { + struct request *rq; + + rq = list_entry(local_list.next, struct request, donelist); + list_del_init(&rq->donelist); + rq->q->softirq_done_fn(rq); + } +} + +/** + * blk_complete_request - end I/O on a request + * @req: the request being processed + * + * Description: + * Ends all I/O on a request. It does not handle partial completions, + * unless the driver actually implements this in its completion callback + * through requeueing. The actual completion happens out-of-order, + * through a softirq handler. The user must have registered a completion + * callback through blk_queue_softirq_done(). + **/ + +void blk_complete_request(struct request *req) +{ + struct list_head *cpu_list; + unsigned long flags; + + BUG_ON(!req->q->softirq_done_fn); + + local_irq_save(flags); + + cpu_list = &__get_cpu_var(blk_cpu_done); + list_add_tail(&req->donelist, cpu_list); + raise_softirq_irqoff(BLOCK_SOFTIRQ); + + local_irq_restore(flags); +} +EXPORT_SYMBOL(blk_complete_request); + +int __init blk_softirq_init(void) +{ + int i; + + for_each_possible_cpu(i) + INIT_LIST_HEAD(&per_cpu(blk_cpu_done, i)); + + open_softirq(BLOCK_SOFTIRQ, blk_done_softirq, NULL); + register_hotcpu_notifier(&blk_cpu_notifier); + return 0; +} +subsys_initcall(blk_softirq_init); -- 1.5.4.22.g7a20 -- 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/