diff options
| author | Shaohua Li <shli@fb.com> | 2017-07-12 20:49:55 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2017-07-29 17:00:03 +0200 |
| commit | 69fd5c391763bd94a40dd152bc72a7f230137150 (patch) | |
| tree | 9f44111556c0f8ac14410703a79c42289ea768c2 /kernel | |
| parent | block: always attach cgroup info into bio (diff) | |
| download | linux-69fd5c391763bd94a40dd152bc72a7f230137150.tar.xz linux-69fd5c391763bd94a40dd152bc72a7f230137150.zip | |
blktrace: add an option to allow displaying cgroup path
By default we output cgroup id in blktrace. This adds an option to
display cgroup path. Since get cgroup path is a relativly heavy
operation, we don't enable it by default.
with the option enabled, blktrace will output something like this:
dd-1353 [007] d..2 293.015252: 8,0 /test/level D R 24 + 8 [dd]
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/cgroup/cgroup.c | 12 | ||||
| -rw-r--r-- | kernel/trace/blktrace.c | 14 |
2 files changed, 25 insertions, 1 deletions
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 6cefa277f39c..2aba1c519138 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -4701,6 +4701,18 @@ static int __init cgroup_wq_init(void) } core_initcall(cgroup_wq_init); +void cgroup_path_from_kernfs_id(const union kernfs_node_id *id, + char *buf, size_t buflen) +{ + struct kernfs_node *kn; + + kn = kernfs_get_node_by_id(cgrp_dfl_root.kf_root, id); + if (!kn) + return; + kernfs_path(kn, buf, buflen); + kernfs_put(kn); +} + /* * proc_cgroup_show() * - Print task's cgroup paths into seq_file, one line for each hierarchy diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index f393d7a43695..e90974ed4532 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -48,12 +48,14 @@ static __cacheline_aligned_in_smp DEFINE_SPINLOCK(running_trace_lock); /* Select an alternative, minimalistic output than the original one */ #define TRACE_BLK_OPT_CLASSIC 0x1 #define TRACE_BLK_OPT_CGROUP 0x2 +#define TRACE_BLK_OPT_CGNAME 0x4 static struct tracer_opt blk_tracer_opts[] = { /* Default disable the minimalistic output */ { TRACER_OPT(blk_classic, TRACE_BLK_OPT_CLASSIC) }, #ifdef CONFIG_BLK_CGROUP { TRACER_OPT(blk_cgroup, TRACE_BLK_OPT_CGROUP) }, + { TRACER_OPT(blk_cgname, TRACE_BLK_OPT_CGNAME) }, #endif { } }; @@ -1213,7 +1215,17 @@ static void blk_log_action(struct trace_iterator *iter, const char *act, if (has_cg) { const union kernfs_node_id *id = cgid_start(iter->ent); - trace_seq_printf(&iter->seq, "%3d,%-3d %x,%-x %2s %3s ", + if (blk_tracer_flags.val & TRACE_BLK_OPT_CGNAME) { + char blkcg_name_buf[NAME_MAX + 1] = "<...>"; + + cgroup_path_from_kernfs_id(id, blkcg_name_buf, + sizeof(blkcg_name_buf)); + trace_seq_printf(&iter->seq, "%3d,%-3d %s %2s %3s ", + MAJOR(t->device), MINOR(t->device), + blkcg_name_buf, act, rwbs); + } else + trace_seq_printf(&iter->seq, + "%3d,%-3d %x,%-x %2s %3s ", MAJOR(t->device), MINOR(t->device), id->ino, id->generation, act, rwbs); } else |