From 9ad1a74ff0090fb201ee87ebb00b38c8bf25b26c Mon Sep 17 00:00:00 2001
From: Logan Gunthorpe <logang@deltatee.com>
Date: Thu, 16 Jun 2022 13:19:45 -0600
Subject: [PATCH] md/raid5: Increase restriction on max segments per request
Git-commit: 9ad1a74ff0090fb201ee87ebb00b38c8bf25b26c
Patch-mainline: v6.0-rc1
References: jsc#PED-2766
The block layer defaults the maximum segments to 128, which means
requests tend to get split around the 512KB depending on how many
pages can be merged. There's no such restriction in the raid5 code
so increase the limit to USHRT_MAX so that larger requests can be
sent as one.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Coly Li <colyli@suse.de>
---
drivers/md/raid5.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 651a84bf1a13..00cab9e525f1 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -8008,6 +8008,9 @@ static int raid5_run(struct mddev *mddev)
*/
blk_queue_max_hw_sectors(mddev->queue,
RAID5_MAX_REQ_STRIPES << RAID5_STRIPE_SHIFT(conf));
+
+ /* No restrictions on the number of segments in the request */
+ blk_queue_max_segments(mddev->queue, USHRT_MAX);
}
if (log_init(conf, journal_dev, raid5_has_ppl(conf)))
--
2.35.3