103 lines
3.0 KiB
Diff
103 lines
3.0 KiB
Diff
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: block/mq: don't complete requests via IPI
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Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.8/older/patches-4.8.6-rt5.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 | 20 ++++++++++++++++++++
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include/linux/blk-mq.h | 1 +
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include/linux/blkdev.h | 1 +
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4 files changed, 25 insertions(+)
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--- a/block/blk-core.c
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+++ b/block/blk-core.c
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@@ -125,6 +125,9 @@ void blk_rq_init(struct request_queue *q
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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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--- a/block/blk-mq.c
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+++ b/block/blk-mq.c
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@@ -197,6 +197,9 @@ static void blk_mq_rq_ctx_init(struct re
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rq->resid_len = 0;
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rq->sense = NULL;
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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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@@ -379,6 +382,17 @@ void blk_mq_end_request(struct request *
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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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@@ -386,6 +400,8 @@ static void __blk_mq_complete_request_re
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rq->q->softirq_done_fn(rq);
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}
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+#endif
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+
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static void blk_mq_ipi_complete_request(struct request *rq)
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{
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struct blk_mq_ctx *ctx = rq->mq_ctx;
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@@ -402,10 +418,14 @@ static void blk_mq_ipi_complete_request(
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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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+ 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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--- a/include/linux/blk-mq.h
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+++ b/include/linux/blk-mq.h
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@@ -222,6 +222,7 @@ static inline u16 blk_mq_unique_tag_to_t
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struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *, const int ctx_index);
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struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_tag_set *, unsigned int, int);
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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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--- a/include/linux/blkdev.h
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+++ b/include/linux/blkdev.h
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@@ -89,6 +89,7 @@ struct request {
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struct list_head queuelist;
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union {
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struct call_single_data csd;
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+ struct work_struct work;
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u64 fifo_time;
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};
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