>From 8c6417cb56c71efd47d28d15bc117567f3171c93 Mon Sep 17 00:00:00 2001 From: Tejun Heo <[email protected]> Date: Thu, 16 Jul 2015 11:50:49 -0400
The recent percpu conversion of blkg_rwstat triggered the following warning in certain configurations. block/blk-cgroup.c:654:1: warning: the frame size of 1360 bytes is larger than 1024 bytes This is because blkg_rwstat now contains four percpu_counter which can be pretty big depending on debug options although it shouldn't be a problem in production configs. This patch removes one of the two local blkg_rwstat variables used by blkg_rwstat_recursive_sum() to reduce stack usage. Signed-off-by: Tejun Heo <[email protected]> Cc: Vivek Goyal <[email protected]> Reported-by: kbuild test robot <[email protected]> Link: http://article.gmane.org/gmane.linux.kernel.cgroups/13835 --- Hello, One extra patch to deal with stack usage bloat under debug configs which came with percpu_counter conversion. git branch updated accordingly. Thanks. block/blk-cgroup.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 2469a65..0d5b8b8 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -744,7 +744,7 @@ struct blkg_rwstat blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, rcu_read_lock(); blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) { - struct blkg_rwstat *rwstat, tmp; + struct blkg_rwstat *rwstat; if (!pos_blkg->online) continue; @@ -754,12 +754,10 @@ struct blkg_rwstat blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, else rwstat = (void *)pos_blkg + off; - tmp = blkg_rwstat_read(rwstat); - for (i = 0; i < BLKG_RWSTAT_NR; i++) - atomic64_add(atomic64_read(&tmp.aux_cnt[i]) + - atomic64_read(&rwstat->aux_cnt[i]), - &sum.aux_cnt[i]); + atomic64_add(atomic64_read(&rwstat->aux_cnt[i]) + + percpu_counter_sum_positive(&rwstat->cpu_cnt[i]), + &sum.aux_cnt[i]); } rcu_read_unlock(); -- 2.4.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
