Hi Jens, Any comments on this patch and the related patch set for blktrace [1] ? Regards, Tao [1]: https://www.spinics.net/lists/linux-btrace/msg00790.html On 2018/1/11 12:09, Hou Tao wrote: > Now blktrace supports outputting cgroup info for trace action and > trace message, however, it can only be enabled globally by writing > "blk_cgroup" to trace_options file, and there is no per-device API > for the new functionality. > > Adding a new field (enable_cg_info) by using the pad after act_mask > in struct blk_user_trace_setup and a new attr file (cgroup_info) under > /sys/block/$dev/trace dir, so BLKTRACESETUP ioctl and sysfs file > can be used to enable cgroup info for selected block devices. > > Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx> > --- > include/linux/blktrace_api.h | 2 ++ > include/uapi/linux/blktrace_api.h | 1 + > kernel/trace/blktrace.c | 14 ++++++++++++-- > 3 files changed, 15 insertions(+), 2 deletions(-) > > diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h > index 8804753..f120c6a 100644 > --- a/include/linux/blktrace_api.h > +++ b/include/linux/blktrace_api.h > @@ -18,6 +18,7 @@ struct blk_trace { > unsigned long __percpu *sequence; > unsigned char __percpu *msg_data; > u16 act_mask; > + bool enable_cg_info; > u64 start_lba; > u64 end_lba; > u32 pid; > @@ -102,6 +103,7 @@ static inline int blk_trace_init_sysfs(struct device *dev) > struct compat_blk_user_trace_setup { > char name[BLKTRACE_BDEV_SIZE]; > u16 act_mask; > + u8 enable_cg_info; > u32 buf_size; > u32 buf_nr; > compat_u64 start_lba; > diff --git a/include/uapi/linux/blktrace_api.h b/include/uapi/linux/blktrace_api.h > index 20d1490d..d9d9fca 100644 > --- a/include/uapi/linux/blktrace_api.h > +++ b/include/uapi/linux/blktrace_api.h > @@ -136,6 +136,7 @@ enum { > struct blk_user_trace_setup { > char name[BLKTRACE_BDEV_SIZE]; /* output */ > __u16 act_mask; /* input */ > + __u8 enable_cg_info; /* input */ > __u32 buf_size; /* input */ > __u32 buf_nr; /* input */ > __u64 start_lba; > diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c > index 987d9a9a..f420400 100644 > --- a/kernel/trace/blktrace.c > +++ b/kernel/trace/blktrace.c > @@ -180,7 +180,8 @@ void __trace_note_message(struct blk_trace *bt, struct blkcg *blkcg, > n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args); > va_end(args); > > - if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP)) > + if (!((blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP) || > + bt->enable_cg_info)) > blkcg = NULL; > #ifdef CONFIG_BLK_CGROUP > trace_note(bt, 0, BLK_TN_MESSAGE, buf, n, > @@ -549,6 +550,7 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, > bt->act_mask = buts->act_mask; > if (!bt->act_mask) > bt->act_mask = (u16) -1; > + bt->enable_cg_info = buts->enable_cg_info; > > blk_trace_setup_lba(bt, bdev); > > @@ -625,6 +627,7 @@ static int compat_blk_trace_setup(struct request_queue *q, char *name, > > buts = (struct blk_user_trace_setup) { > .act_mask = cbuts.act_mask, > + .enable_cg_info = cbuts.enable_cg_info, > .buf_size = cbuts.buf_size, > .buf_nr = cbuts.buf_nr, > .start_lba = cbuts.start_lba, > @@ -773,7 +776,8 @@ blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio) > { > struct blk_trace *bt = q->blk_trace; > > - if (!bt || !(blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP)) > + if (!(bt && (bt->enable_cg_info || > + (blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP)))) > return NULL; > > if (!bio->bi_css) > @@ -1664,6 +1668,7 @@ static BLK_TRACE_DEVICE_ATTR(act_mask); > static BLK_TRACE_DEVICE_ATTR(pid); > static BLK_TRACE_DEVICE_ATTR(start_lba); > static BLK_TRACE_DEVICE_ATTR(end_lba); > +static BLK_TRACE_DEVICE_ATTR(cgroup_info); > > static struct attribute *blk_trace_attrs[] = { > &dev_attr_enable.attr, > @@ -1671,6 +1676,7 @@ static struct attribute *blk_trace_attrs[] = { > &dev_attr_pid.attr, > &dev_attr_start_lba.attr, > &dev_attr_end_lba.attr, > + &dev_attr_cgroup_info.attr, > NULL > }; > > @@ -1794,6 +1800,8 @@ static ssize_t sysfs_blk_trace_attr_show(struct device *dev, > ret = sprintf(buf, "%llu\n", q->blk_trace->start_lba); > else if (attr == &dev_attr_end_lba) > ret = sprintf(buf, "%llu\n", q->blk_trace->end_lba); > + else if (attr == &dev_attr_cgroup_info) > + ret = sprintf(buf, "%u\n", q->blk_trace->enable_cg_info); > > out_unlock_bdev: > mutex_unlock(&q->blk_trace_mutex); > @@ -1861,6 +1869,8 @@ static ssize_t sysfs_blk_trace_attr_store(struct device *dev, > q->blk_trace->start_lba = value; > else if (attr == &dev_attr_end_lba) > q->blk_trace->end_lba = value; > + else if (attr == &dev_attr_cgroup_info) > + q->blk_trace->enable_cg_info = !!value; > } > > out_unlock_bdev: >
