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Update patch from Ming to match latest upstream submission

This commit is contained in:
Justin M. Forbes 2015-05-01 08:49:46 -05:00
parent 8f12f4a6b4
commit 41237e1e4b
1 changed files with 9 additions and 14 deletions
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23
blk-loop-avoid-too-many-pending-per-work-IO.patch
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@ -1,7 +1,3 @@
From: Ming Lei <ming.lei@canonical.com>
Date: Tue, 28 Apr 2015 14:40:49 -0400
Subject: [PATCH] blk: loop: avoid too many pending work IO
If there are too many pending per work I/O, too many
high priority work thread can be generated so that
system performance can be effected.
@ -36,10 +32,10 @@ Signed-off-by: Ming Lei <ming.lei@canonical.com>
2 files changed, 19 insertions(+), 2 deletions(-)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index d1f168b73634..453bceec22f9 100644
index ae3fcb4..5a728c6 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1477,13 +1477,24 @@ static int loop_queue_rq(struct blk_mq_hw_ctx *hctx,
@@ -1425,13 +1425,24 @@ static int loop_queue_rq(struct blk_mq_hw_ctx *hctx,
const struct blk_mq_queue_data *bd)
{
struct loop_cmd *cmd = blk_mq_rq_to_pdu(bd->rq);
@ -48,11 +44,11 @@ index d1f168b73634..453bceec22f9 100644
+
+ /*
+ * Fallback to single queue mode if the pending per work
+ * I/O number reaches 32, otherwise too many high priority
+ * I/O number reaches 16, otherwise too many high priority
+ * worker thread may effect system performance as reported
+ * in fedora live booting from squashfs over loop.
+ */
+ if (atomic_read(&lo->pending_per_work_io) >= 32)
+ if (atomic_read(&lo->pending_per_work_io) >= 16)
+ single_queue = true;
blk_mq_start_request(bd->rq);
@ -66,16 +62,16 @@ index d1f168b73634..453bceec22f9 100644
spin_lock_irq(&lo->lo_lock);
if (lo->write_started)
need_sched = false;
@@ -1495,6 +1506,8 @@ static int loop_queue_rq(struct blk_mq_hw_ctx *hctx,
@@ -1443,6 +1454,8 @@ static int loop_queue_rq(struct blk_mq_hw_ctx *hctx,
if (need_sched)
queue_work(loop_wq, &lo->write_work);
} else {
+ cmd->per_work_io = true;
+ atomic_inc(&lo->pending_per_work_io);
+ cmd->per_work_io = true;
queue_work(loop_wq, &cmd->read_work);
}
@@ -1519,6 +1532,8 @@ static void loop_handle_cmd(struct loop_cmd *cmd)
@@ -1467,6 +1480,8 @@ static void loop_handle_cmd(struct loop_cmd *cmd)
if (ret)
cmd->rq->errors = -EIO;
blk_mq_complete_request(cmd->rq);
@ -85,7 +81,7 @@ index d1f168b73634..453bceec22f9 100644
static void loop_queue_write_work(struct work_struct *work)
diff --git a/drivers/block/loop.h b/drivers/block/loop.h
index 301c27f8323f..eb855f57a62d 100644
index 301c27f..eb855f5 100644
--- a/drivers/block/loop.h
+++ b/drivers/block/loop.h
@@ -57,6 +57,7 @@ struct loop_device {
@ -105,5 +101,4 @@ index 301c27f8323f..eb855f57a62d 100644
};
--
2.1.0
1.9.1