From: Abd-Alrhman Masalkhi <abd.masalkhi@gmail.com>
Date: Tue, 27 Jul 2021 08:25:13 +0200
Subject: [PATCH] block: reduce stack usage in diskstats_show
Git-commit: 26e2d7a362f6a83146ea3eaa8f17ca9ce35388d3
Patch-mainline: v5.15-rc1
References: jsc#PED-1183
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: Abd-Alrhman Masalkhi <abd.masalkhi@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20210727062518.122108-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Hannes Reinecke <hare@suse.com>
---
block/genhd.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/block/genhd.c b/block/genhd.c
index 5dbb99b57b33..cf705cf95440 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -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],
--
2.35.3