From: Nitesh Shetty <nj.shetty@samsung.com>
To: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: axboe@kernel.dk, axboe@fb.com, linux-nvme@lists.infradead.org,
nj.shetty@samsung.com, joshi.k@samsung.com
Subject: [PATCH v2 RESENT] blk: optimization for classic polling
Date: Wed, 14 Feb 2018 00:26:46 +0530 [thread overview]
Message-ID: <1518548206-4766-1-git-send-email-nj.shetty@samsung.com> (raw)
In-Reply-To: <3578876466-3733-1-git-send-email-nj.shetty@samsung.com>
This removes the dependency on interrupts to wake up task. Set task
state as TASK_RUNNING, if need_resched() returns true,
while polling for IO completion.
Earlier, polling task used to sleep, relying on interrupt to wake it up.
This made some IO take very long when interrupt-coalescing is enabled in
NVMe.
Reference:
http://lists.infradead.org/pipermail/linux-nvme/2018-February/015435.html
Changes since v1:
-setting task state once in blk_poll, instead of multiple
callers.
Signed-off-by: Nitesh Shetty <nj.shetty@samsung.com>
---
block/blk-mq.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index df93102..40285fe 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -3164,6 +3164,7 @@ static bool __blk_mq_poll(struct blk_mq_hw_ctx *hctx, struct request *rq)
cpu_relax();
}
+ set_current_state(TASK_RUNNING);
return false;
}
--
2.7.4
WARNING: multiple messages have this Message-ID (diff)
From: nj.shetty@samsung.com (Nitesh Shetty)
Subject: [PATCH v2 RESENT] blk: optimization for classic polling
Date: Wed, 14 Feb 2018 00:26:46 +0530 [thread overview]
Message-ID: <1518548206-4766-1-git-send-email-nj.shetty@samsung.com> (raw)
In-Reply-To: <3578876466-3733-1-git-send-email-nj.shetty@samsung.com>
This removes the dependency on interrupts to wake up task. Set task
state as TASK_RUNNING, if need_resched() returns true,
while polling for IO completion.
Earlier, polling task used to sleep, relying on interrupt to wake it up.
This made some IO take very long when interrupt-coalescing is enabled in
NVMe.
Reference:
http://lists.infradead.org/pipermail/linux-nvme/2018-February/015435.html
Changes since v1:
-setting task state once in blk_poll, instead of multiple
callers.
Signed-off-by: Nitesh Shetty <nj.shetty at samsung.com>
---
block/blk-mq.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index df93102..40285fe 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -3164,6 +3164,7 @@ static bool __blk_mq_poll(struct blk_mq_hw_ctx *hctx, struct request *rq)
cpu_relax();
}
+ set_current_state(TASK_RUNNING);
return false;
}
--
2.7.4
next prev parent reply other threads:[~2018-02-13 8:27 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20180208143655epcas1p444bf34705526b7839a5a135f82761aad@epcas1p4.samsung.com>
2018-02-08 14:37 ` [PATCH] blk: optimization for classic polling Nitesh Shetty
2083-05-30 4:21 ` Nitesh Shetty
2018-02-08 15:27 ` Keith Busch
2018-02-08 15:27 ` Keith Busch
2018-02-08 15:27 ` Keith Busch
2018-02-08 16:03 ` Sagi Grimberg
2018-02-08 16:03 ` Sagi Grimberg
2018-02-12 15:50 ` Bart Van Assche
2018-02-12 15:50 ` Bart Van Assche
[not found] ` <CGME20180213154752epcas1p35e3c13d150d2108a06342781ec5e64d7@epcas1p3.samsung.com>
2018-02-13 15:48 ` [PATCH v3] " Nitesh Shetty
2018-02-13 15:48 ` Nitesh Shetty
2018-02-13 16:12 ` Jens Axboe
2018-02-13 16:12 ` Jens Axboe
[not found] ` <CGME20180213082701epcas1p4d92a86f127a0918fb9d62120bd121cb6@epcas1p4.samsung.com>
2018-02-13 18:56 ` Nitesh Shetty [this message]
2018-02-13 18:56 ` [PATCH v2 RESENT] " Nitesh Shetty
2018-02-13 14:42 ` Jens Axboe
2018-02-13 14:42 ` Jens Axboe
2018-02-20 13:21 ` [PATCH] " Peter Zijlstra
2018-02-20 13:21 ` Peter Zijlstra
2018-02-20 16:27 ` Keith Busch
2018-02-20 16:27 ` Keith Busch
2018-02-20 22:37 ` Jens Axboe
2018-02-20 22:37 ` Jens Axboe
2018-02-21 8:32 ` Peter Zijlstra
2018-02-21 8:32 ` Peter Zijlstra
2018-10-10 18:52 ` Florian Fainelli
2018-10-10 18:52 ` Florian Fainelli
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