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From: Yiming Xu <teddyxym@outlook.com>
To: majordomo@vger.kernel.org
Cc: linux-raid@vger.kernel.org, paul.e.luse@intel.com,
	firnyee@gmail.com, song@kernel.org, hch@infradead.org,
	Yiming Xu <teddyxym@outlook.com>
Subject: [RFC V2 1/2] md/raid5: optimize RAID5 performance.
Date: Wed,  3 Apr 2024 01:05:46 +0800	[thread overview]
Message-ID: <SJ0PR10MB574146BF65CC516F253B2DADD83E2@SJ0PR10MB5741.namprd10.prod.outlook.com> (raw)

From: Shushu Yi <firnyee@gmail.com>

<changelog>

Optimized by using fine-grained locks, customized data structures, and
scattered address space. Achieves significant improvements in both
throughput and latency.

This patch attempts to maximize thread-level parallelism and reduce
CPU suspension time caused by lock contention. On a system with four
PCIe 4.0 SSDs, we achieved increased overall storage throughput by
89.4% and decreases the 99.99th percentile I/O latency by 85.4%.

Seeking feedback on the approach and any addition information regarding
Required performance testing before submitting a formal patch.

Note: this work has been published as a paper, and the URL is
(https://www.hotstorage.org/2022/camera-ready/hotstorage22-5/pdf/
hotstorage22-5.pdf)

Co-developed-by: Yiming Xu <teddyxym@outlook.com>
Signed-off-by: Yiming Xu <teddyxym@outlook.com>
Signed-off-by: Shushu Yi <firnyee@gmail.com>
Tested-by: Paul Luse <paul.e.luse@intel.com>
---
V1 -> V2: Cleaned up coding style and divided into 2 patches (HemiRAID
and ScalaRAID corresponding to the paper mentioned above). This part is
HemiRAID, which increased the number of stripe locks to 128.

 drivers/md/raid5.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index 9b5a7dc3f2a0..d26da031d203 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -501,7 +501,7 @@ struct disk_info {
  * and creating that much locking depth can cause
  * problems.
  */
-#define NR_STRIPE_HASH_LOCKS 8
+#define NR_STRIPE_HASH_LOCKS 128
 #define STRIPE_HASH_LOCKS_MASK (NR_STRIPE_HASH_LOCKS - 1)
 
 struct r5worker {
-- 
2.34.1


             reply	other threads:[~2024-04-02 17:06 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-02 17:05 Yiming Xu [this message]
2024-04-02 17:19 ` [RFC V2 1/2] md/raid5: optimize RAID5 performance Paul Menzel

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