Blame SOURCES/seabios-virtio-blk-use-larger-default-request-size.patch

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From 7ef00c50cafaf356b9aef5f7c7865b405de6b2f5 Mon Sep 17 00:00:00 2001
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From: Gerd Hoffmann <kraxel@redhat.com>
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Date: Thu, 30 Jun 2022 17:28:40 +0200
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Subject: [PATCH] virtio-blk: use larger default request size
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RH-Author: Gerd Hoffmann <kraxel@redhat.com>
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RH-MergeRequest: 5: virtio-blk: use larger default request size
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RH-Commit: [1/1] 5b2833de23fdab9fc3c170e448e9ed07d9fb82dd (kraxel/centos-seabios)
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RH-Bugzilla: 2108555
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RH-Acked-by: Oliver Steffen <osteffen@redhat.com>
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RH-Acked-by: Pawel Polawski <ppolawsk@redhat.com>
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RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
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Bump default from 8 to 64 blocks.  Using 8 by default leads
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to requests being splitted on qemu, which slows down boot.
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Some (temporary) debug logging added showed that almost all
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requests on a standard fedora install are less than 64 blocks,
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so that should bring us back to 1.15 performance levels.
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Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
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(cherry picked from commit 46de2eec93bffa0706e6229c0da2919763c8eb04)
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---
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 src/hw/virtio-blk.c | 2 +-
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 1 file changed, 1 insertion(+), 1 deletion(-)
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diff --git a/src/hw/virtio-blk.c b/src/hw/virtio-blk.c
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index 929ba887..9b4a05a4 100644
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--- a/src/hw/virtio-blk.c
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+++ b/src/hw/virtio-blk.c
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@@ -95,7 +95,7 @@ virtio_blk_op(struct disk_op_s *op, int write)
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         blk_num_max = (u16)max_io_size / vdrive->drive.blksize;
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     else
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         /* default blk_num_max if hardware doesnot advise a proper value */
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-        blk_num_max = 8;
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+        blk_num_max = 64;
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     if (op->count <= blk_num_max) {
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         virtio_blk_op_one_segment(vdrive, write, sg);
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-- 
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2.31.1
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