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authorTejun Heo <tj@kernel.org>2019-11-04 15:54:30 -0800
committerTejun Heo <tj@kernel.org>2019-11-12 08:18:04 -0800
commit743210386c0354a2f8ef3d697353c7d8477fa81d (patch)
treeac8071135c3e67ff425391540eb88c7dc343afb7 /kernel/trace
parent40430452fd5da1509177ac597b394614cd3a121f (diff)
downloadlinux-743210386c0354a2f8ef3d697353c7d8477fa81d.tar.bz2
cgroup: use cgrp->kn->id as the cgroup ID
cgroup ID is currently allocated using a dedicated per-hierarchy idr and used internally and exposed through tracepoints and bpf. This is confusing because there are tracepoints and other interfaces which use the cgroupfs ino as IDs. The preceding changes made kn->id exposed as ino as 64bit ino on supported archs or ino+gen (low 32bits as ino, high gen). There's no reason for cgroup to use different IDs. The kernfs IDs are unique and userland can easily discover them and map them back to paths using standard file operations. This patch replaces cgroup IDs with kernfs IDs. * cgroup_id() is added and all cgroup ID users are converted to use it. * kernfs_node creation is moved to earlier during cgroup init so that cgroup_id() is available during init. * While at it, s/cgroup/cgrp/ in psi helpers for consistency. * Fallback ID value is changed to 1 to be consistent with root cgroup ID. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Namhyung Kim <namhyung@kernel.org>
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/blktrace.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index a7dac5b63f3f..475e29498bca 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -171,7 +171,7 @@ void __trace_note_message(struct blk_trace *bt, struct blkcg *blkcg,
blkcg = NULL;
#ifdef CONFIG_BLK_CGROUP
trace_note(bt, 0, BLK_TN_MESSAGE, buf, n,
- blkcg ? cgroup_get_kernfs_id(blkcg->css.cgroup) : 0);
+ blkcg ? cgroup_id(blkcg->css.cgroup) : 1);
#else
trace_note(bt, 0, BLK_TN_MESSAGE, buf, n, 0);
#endif
@@ -759,7 +759,7 @@ static u64 blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio)
if (!bio->bi_blkg)
return 0;
- return cgroup_get_kernfs_id(bio_blkcg(bio)->css.cgroup);
+ return cgroup_id(bio_blkcg(bio)->css.cgroup);
}
#else
u64 blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio)