Patch "block: unalign call_single_data in struct request" has been added to the 4.14-stable tree

Patch "block: unalign call_single_data in struct request" has been added to the 4.14-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    block: unalign call_single_data in struct request

to the 4.14-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     block-unalign-call_single_data-in-struct-request.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 4ccafe032005e9b96acbef2e389a4de5b1254add Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Wed, 20 Dec 2017 13:13:58 -0700
Subject: block: unalign call_single_data in struct request

From: Jens Axboe <axboe@kernel.dk>

commit 4ccafe032005e9b96acbef2e389a4de5b1254add upstream.

A previous change blindly added massive alignment to the
call_single_data structure in struct request. This ballooned it in size
from 296 to 320 bytes on my setup, for no valid reason at all.

Use the unaligned struct __call_single_data variant instead.

Fixes: 966a967116e69 ("smp: Avoid using two cache lines for struct call_single_data")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 include/linux/blkdev.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -135,7 +135,7 @@ typedef __u32 __bitwise req_flags_t;
 struct request {
 	struct list_head queuelist;
 	union {
-		call_single_data_t csd;
+		struct __call_single_data csd;
 		u64 fifo_time;
 	};
 


Patches currently in stable-queue which might be from axboe@kernel.dk are

queue-4.14/block-unalign-call_single_data-in-struct-request.patch
queue-4.14/block-throttle-avoid-double-charge.patch