hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I4R7RE CVE: NA

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blkio subsytem is not under default hierarchy in cgroup v1 by default, which means configurations will only be effective on current cgroup for io throttle.

This patch introduces a new feature that enable default hierarchy for io throttle, which means configurations will be effective on child cgroups. Such feature is disabled by default, and can be enabled by adding "blkcg_global_limit=1" or "blkcg_global_limit=Y" or "blkcg_global_limit=y" in boot cmd.

Signed-off-by: Yu Kuai yukuai3@huawei.com Reviewed-by: Tao Hou houtao1@huawei.com --- block/blk-throttle.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 13e4377a8b28..c3bd159163d7 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -41,6 +41,19 @@ /* A workqueue to queue throttle related work */ static struct workqueue_struct *kthrotld_workqueue;

+/* True if global limit is enabled in cgroup v1 */ +static bool global_limit; + +static int __init setup_global_limit(char *str) +{ + if (!strcmp(str, "1") || !strcmp(str, "Y") || !strcmp(str, "y")) + global_limit = true; + + return 1; +} + +__setup("blkcg_global_limit=", setup_global_limit); + #define rb_entry_tg(node) rb_entry((node), struct throtl_grp, rb_node)

/* We measure latency for request size from <= 4k to >= 1M */ @@ -405,7 +418,8 @@ static void throtl_pd_init(struct blkg_policy_data *pd) * regardless of the position of the group in the hierarchy. */ sq->parent_sq = &td->service_queue; - if (cgroup_subsys_on_dfl(io_cgrp_subsys) && blkg->parent) + if ((cgroup_subsys_on_dfl(io_cgrp_subsys) || global_limit) && + blkg->parent) sq->parent_sq = &blkg_to_tg(blkg->parent)->service_queue; tg->td = td; }