Jetpack/kernel/kernel-4.9/rt-patches/0215-block-mq-don-t-complet...

115 lines
3.3 KiB
Diff

From 90405f93f5587e649ee2c2882654e95eb62fcbb5 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Thu, 29 Jan 2015 15:10:08 +0100
Subject: [PATCH 215/352] block/mq: don't complete requests via IPI
The IPI runs in hardirq context and there are sleeping locks. This patch
moves the completion into a workqueue.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
block/blk-core.c | 3 +++
block/blk-mq.c | 20 ++++++++++++++++++++
include/linux/blk-mq.h | 2 +-
include/linux/blkdev.h | 1 +
4 files changed, 25 insertions(+), 1 deletion(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 14e305d..f06f03a 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -127,6 +127,9 @@ void blk_rq_init(struct request_queue *q, struct request *rq)
INIT_LIST_HEAD(&rq->queuelist);
INIT_LIST_HEAD(&rq->timeout_list);
+#ifdef CONFIG_PREEMPT_RT_FULL
+ INIT_WORK(&rq->work, __blk_mq_complete_request_remote_work);
+#endif
rq->cpu = -1;
rq->q = q;
rq->__sector = (sector_t) -1;
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 29a25ab..25c6919 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -184,6 +184,9 @@ static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
rq->resid_len = 0;
rq->sense = NULL;
+#ifdef CONFIG_PREEMPT_RT_FULL
+ INIT_WORK(&rq->work, __blk_mq_complete_request_remote_work);
+#endif
INIT_LIST_HEAD(&rq->timeout_list);
rq->timeout = 0;
@@ -352,6 +355,17 @@ void blk_mq_end_request(struct request *rq, int error)
}
EXPORT_SYMBOL(blk_mq_end_request);
+#ifdef CONFIG_PREEMPT_RT_FULL
+
+void __blk_mq_complete_request_remote_work(struct work_struct *work)
+{
+ struct request *rq = container_of(work, struct request, work);
+
+ rq->q->softirq_done_fn(rq);
+}
+
+#else
+
static void __blk_mq_complete_request_remote(void *data)
{
struct request *rq = data;
@@ -359,6 +373,8 @@ static void __blk_mq_complete_request_remote(void *data)
rq->q->softirq_done_fn(rq);
}
+#endif
+
static void blk_mq_ipi_complete_request(struct request *rq)
{
struct blk_mq_ctx *ctx = rq->mq_ctx;
@@ -375,10 +391,14 @@ static void blk_mq_ipi_complete_request(struct request *rq)
shared = cpus_share_cache(cpu, ctx->cpu);
if (cpu != ctx->cpu && !shared && cpu_online(ctx->cpu)) {
+#ifdef CONFIG_PREEMPT_RT_FULL
+ schedule_work_on(ctx->cpu, &rq->work);
+#else
rq->csd.func = __blk_mq_complete_request_remote;
rq->csd.info = rq;
rq->csd.flags = 0;
smp_call_function_single_async(ctx->cpu, &rq->csd);
+#endif
} else {
rq->q->softirq_done_fn(rq);
}
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 00b4043..4498f82 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -209,7 +209,7 @@ static inline u16 blk_mq_unique_tag_to_tag(u32 unique_tag)
return unique_tag & BLK_MQ_UNIQUE_TAG_MASK;
}
-
+void __blk_mq_complete_request_remote_work(struct work_struct *work);
int blk_mq_request_started(struct request *rq);
void blk_mq_start_request(struct request *rq);
void blk_mq_end_request(struct request *rq, int error);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 657689d..7b18f20 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -89,6 +89,7 @@ struct request {
struct list_head queuelist;
union {
struct call_single_data csd;
+ struct work_struct work;
u64 fifo_time;
};
--
2.7.4