123 lines
3.8 KiB
Diff
123 lines
3.8 KiB
Diff
From 42c577ea7a4354ce8a63cfc11579a99a9a8d60c2 Mon Sep 17 00:00:00 2001
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Message-Id: <42c577ea7a4354ce8a63cfc11579a99a9a8d60c2.1601675152.git.zanussi@kernel.org>
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In-Reply-To: <5b5a156f9808b1acf1205606e03da117214549ea.1601675151.git.zanussi@kernel.org>
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References: <5b5a156f9808b1acf1205606e03da117214549ea.1601675151.git.zanussi@kernel.org>
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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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Date: Thu, 29 Jan 2015 15:10:08 +0100
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Subject: [PATCH 180/333] block/mq: don't complete requests via IPI
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Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.148-rt64.tar.xz
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The IPI runs in hardirq context and there are sleeping locks. This patch
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moves the completion into a workqueue.
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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---
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block/blk-core.c | 3 +++
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block/blk-mq.c | 23 +++++++++++++++++++++++
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include/linux/blk-mq.h | 2 +-
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include/linux/blkdev.h | 3 +++
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4 files changed, 30 insertions(+), 1 deletion(-)
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diff --git a/block/blk-core.c b/block/blk-core.c
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index ce3710404544..8926b5d998fa 100644
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--- a/block/blk-core.c
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+++ b/block/blk-core.c
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@@ -189,6 +189,9 @@ void blk_rq_init(struct request_queue *q, struct request *rq)
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INIT_LIST_HEAD(&rq->queuelist);
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INIT_LIST_HEAD(&rq->timeout_list);
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+#ifdef CONFIG_PREEMPT_RT_FULL
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+ INIT_WORK(&rq->work, __blk_mq_complete_request_remote_work);
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+#endif
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rq->cpu = -1;
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rq->q = q;
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rq->__sector = (sector_t) -1;
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diff --git a/block/blk-mq.c b/block/blk-mq.c
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index 830944372d51..f73b111a4d8f 100644
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--- a/block/blk-mq.c
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+++ b/block/blk-mq.c
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@@ -320,6 +320,9 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
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rq->extra_len = 0;
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rq->__deadline = 0;
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+#ifdef CONFIG_PREEMPT_RT_FULL
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+ INIT_WORK(&rq->work, __blk_mq_complete_request_remote_work);
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+#endif
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INIT_LIST_HEAD(&rq->timeout_list);
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rq->timeout = 0;
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@@ -547,12 +550,24 @@ void blk_mq_end_request(struct request *rq, blk_status_t error)
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}
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EXPORT_SYMBOL(blk_mq_end_request);
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+#ifdef CONFIG_PREEMPT_RT_FULL
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+
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+void __blk_mq_complete_request_remote_work(struct work_struct *work)
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+{
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+ struct request *rq = container_of(work, struct request, work);
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+
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+ rq->q->softirq_done_fn(rq);
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+}
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+
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+#else
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+
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static void __blk_mq_complete_request_remote(void *data)
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{
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struct request *rq = data;
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rq->q->softirq_done_fn(rq);
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}
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+#endif
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static void __blk_mq_complete_request(struct request *rq)
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{
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@@ -575,10 +590,18 @@ static void __blk_mq_complete_request(struct request *rq)
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shared = cpus_share_cache(cpu, ctx->cpu);
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if (cpu != ctx->cpu && !shared && cpu_online(ctx->cpu)) {
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+#ifdef CONFIG_PREEMPT_RT_FULL
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+ /*
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+ * We could force QUEUE_FLAG_SAME_FORCE then we would not get in
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+ * here. But we could try to invoke it one the CPU like this.
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+ */
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+ schedule_work_on(ctx->cpu, &rq->work);
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+#else
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rq->csd.func = __blk_mq_complete_request_remote;
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rq->csd.info = rq;
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rq->csd.flags = 0;
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smp_call_function_single_async(ctx->cpu, &rq->csd);
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+#endif
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} else {
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rq->q->softirq_done_fn(rq);
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}
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diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
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index 2885dce1ad49..8dbb9ecf9993 100644
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--- a/include/linux/blk-mq.h
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+++ b/include/linux/blk-mq.h
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@@ -256,7 +256,7 @@ static inline u16 blk_mq_unique_tag_to_tag(u32 unique_tag)
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return unique_tag & BLK_MQ_UNIQUE_TAG_MASK;
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}
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-
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+void __blk_mq_complete_request_remote_work(struct work_struct *work);
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int blk_mq_request_started(struct request *rq);
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void blk_mq_start_request(struct request *rq);
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void blk_mq_end_request(struct request *rq, blk_status_t error);
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diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
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index 745b2d0dcf78..7cd627f2a016 100644
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--- a/include/linux/blkdev.h
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+++ b/include/linux/blkdev.h
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@@ -149,6 +149,9 @@ enum mq_rq_state {
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*/
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struct request {
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struct request_queue *q;
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+#ifdef CONFIG_PREEMPT_RT_FULL
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+ struct work_struct work;
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+#endif
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struct blk_mq_ctx *mq_ctx;
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int cpu;
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--
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2.17.1
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