[PATCH 1/3] md/raid10: optimize fix_read_error
From: <hidden>
Date: 2023-06-23 09:34:35
Also in:
lkml
Subsystem:
software raid (multiple disks) support, the rest · Maintainers:
Song Liu, Yu Kuai, Linus Torvalds
From: Li Nan <redacted> We dereference r10_bio->read_slot too many times in fix_read_error(). Optimize it by using a variable to store read_slot. Signed-off-by: Li Nan <redacted> --- drivers/md/raid10.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 381c21f7fb06..94ae294c8a3c 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c@@ -2725,10 +2725,10 @@ static int r10_sync_page_io(struct md_rdev *rdev, sector_t sector, static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10bio *r10_bio) { int sect = 0; /* Offset from r10_bio->sector */ - int sectors = r10_bio->sectors; + int sectors = r10_bio->sectors, slot = r10_bio->read_slot; struct md_rdev *rdev; int max_read_errors = atomic_read(&mddev->max_corr_read_errors); - int d = r10_bio->devs[r10_bio->read_slot].devnum; + int d = r10_bio->devs[slot].devnum; /* still own a reference to this rdev, so it cannot * have been cleared recently.
@@ -2749,13 +2749,13 @@ static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10 pr_notice("md/raid10:%s: %pg: Failing raid device\n", mdname(mddev), rdev->bdev); md_error(mddev, rdev); - r10_bio->devs[r10_bio->read_slot].bio = IO_BLOCKED; + r10_bio->devs[slot].bio = IO_BLOCKED; return; } while(sectors) { int s = sectors; - int sl = r10_bio->read_slot; + int sl = slot; int success = 0; int start;
@@ -2790,7 +2790,7 @@ static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10 sl++; if (sl == conf->copies) sl = 0; - } while (!success && sl != r10_bio->read_slot); + } while (!success && sl != slot); rcu_read_unlock(); if (!success) {
@@ -2798,16 +2798,16 @@ static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10 * as bad on the first device to discourage future * reads. */ - int dn = r10_bio->devs[r10_bio->read_slot].devnum; + int dn = r10_bio->devs[slot].devnum; rdev = conf->mirrors[dn].rdev; if (!rdev_set_badblocks( rdev, - r10_bio->devs[r10_bio->read_slot].addr + r10_bio->devs[slot].addr + sect, s, 0)) { md_error(mddev, rdev); - r10_bio->devs[r10_bio->read_slot].bio + r10_bio->devs[slot].bio = IO_BLOCKED; } break;
@@ -2816,7 +2816,7 @@ static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10 start = sl; /* write it back and re-read */ rcu_read_lock(); - while (sl != r10_bio->read_slot) { + while (sl != slot) { if (sl==0) sl = conf->copies; sl--;
@@ -2850,7 +2850,7 @@ static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10 rcu_read_lock(); } sl = start; - while (sl != r10_bio->read_slot) { + while (sl != slot) { if (sl==0) sl = conf->copies; sl--;
--
2.39.2