Commit f3496522 authored Dec 20, 2017 by Jens Axboe Committed by Greg Kroah-Hartman Dec 29, 2017

block: unalign call_single_data in struct request

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: 966a9671 ("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>

parent d8f477a5

include/linux/blkdev.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -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;
		};