linuxkit/kernel/patches-4.14.x-rt/0296-block-mq-don-t-complete-requests-via-IPI.patch
Tiejun Chen a1d47ff766 update -rt to 4.14.53-rt34
Signed-off-by: Tiejun Chen <tiejun.china@gmail.com>
2018-07-06 14:02:07 +08:00

119 lines
3.5 KiB
Diff

From 9ccd4e0d93c504e73e0e35b948b067c70f2268fc 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 296/418] 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 | 23 +++++++++++++++++++++++
include/linux/blk-mq.h | 2 +-
include/linux/blkdev.h | 3 +++
4 files changed, 30 insertions(+), 1 deletion(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 0b7308bce7e7..4ea09f0974d6 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -116,6 +116,9 @@ 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 ff88e0991196..0815a6599ab3 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -339,6 +339,9 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
/* tag was already set */
rq->extra_len = 0;
+#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;
@@ -533,12 +536,24 @@ void blk_mq_end_request(struct request *rq, blk_status_t 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;
rq->q->softirq_done_fn(rq);
}
+#endif
static void __blk_mq_complete_request(struct request *rq)
{
@@ -563,10 +578,18 @@ static void __blk_mq_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
+ /*
+ * We could force QUEUE_FLAG_SAME_FORCE then we would not get in
+ * here. But we could try to invoke it one the CPU like this.
+ */
+ 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 994cbb0f7ffc..0d4b7e3489a9 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -226,7 +226,7 @@ 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, blk_status_t error);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 6362e3606aa5..b68752bfb645 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -134,6 +134,9 @@ typedef __u32 __bitwise req_flags_t;
*/
struct request {
struct list_head queuelist;
+#ifdef CONFIG_PREEMPT_RT_FULL
+ struct work_struct work;
+#endif
union {
struct __call_single_data csd;
u64 fifo_time;
--
2.17.1