Commit 26e2d7a3 authored by Abd-Alrhman Masalkhi's avatar Abd-Alrhman Masalkhi Committed by Jens Axboe
Browse files

block: reduce stack usage in diskstats_show 



I have compiled the kernel with a cross compiler "hppa-linux-gnu-" v9.3.0
on x86-64 host machine. I got the following warning:

block/genhd.c: In function ‘diskstats_show’:
block/genhd.c:1227:1: warning: the frame size of 1688 bytes is larger
than 1280 bytes [-Wframe-larger-than=]
 1227  |  }

By Reduced the stack footprint by using the %pg printk specifier instead
of disk_name to remove the need for the on-stack buffer.

Signed-off-by: default avatarAbd-Alrhman Masalkhi <abd.masalkhi@gmail.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Reviewed-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20210727062518.122108-2-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 2f4731dc

block/genhd.c

+2 −4
Original line number Diff line number Diff line
@@ -1111,7 +1111,6 @@ static int diskstats_show(struct seq_file *seqf, void *v) 
{

	struct gendisk *gp = v;

	struct block_device *hd;

	char buf[BDEVNAME_SIZE];

	unsigned int inflight;

	struct disk_stats stat;

	unsigned long idx;
@@ -1134,15 +1133,14 @@ static int diskstats_show(struct seq_file *seqf, void *v) 
		else

			inflight = part_in_flight(hd);



		seq_printf(seqf, "%4d %7d %s "

		seq_printf(seqf, "%4d %7d %pg "

			   "%lu %lu %lu %u "

			   "%lu %lu %lu %u "

			   "%u %u %u "

			   "%lu %lu %lu %u "

			   "%lu %u"

			   "\n",

			   MAJOR(hd->bd_dev), MINOR(hd->bd_dev),

			   disk_name(gp, hd->bd_partno, buf),

			   MAJOR(hd->bd_dev), MINOR(hd->bd_dev), hd,

			   stat.ios[STAT_READ],

			   stat.merges[STAT_READ],

			   stat.sectors[STAT_READ],