Vivek Goyal wrote:
...
> Hi Gui,
>
> It might make sense to also store the device name or device major and
> minor number in io_group while creating the io group. This will help us
> to display io.disk_time and io.disk_sector statistics per device instead
> of aggregate.
>
> I am attaching a patch I was playing around with to display per device
> statistics instead of aggregate one. So if user has specified the per
> device rule.
>
> Thanks
> Vivek
>
>
> o Currently the statistics exported through cgroup are aggregate of statistics
> on all devices for that cgroup. Instead of aggregate, make these per device.
>
> o Also export another statistics io.disk_dequeue. This keeps a count of how
> many times a particular group got out of race for the disk. This is a
> debugging aid to keep a track how often we could create continuously
> backlogged queues.
>
> Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx>
> ---
> block/elevator-fq.c | 127 +++++++++++++++++++++++++++++++++-------------------
> block/elevator-fq.h | 3 +
> 2 files changed, 85 insertions(+), 45 deletions(-)
>
> Index: linux14/block/elevator-fq.h
> ===================================================================
> --- linux14.orig/block/elevator-fq.h 2009-05-13 11:40:32.000000000 -0400
> +++ linux14/block/elevator-fq.h 2009-05-13 11:40:57.000000000 -0400
> @@ -250,6 +250,9 @@ struct io_group {
>
> #ifdef CONFIG_DEBUG_GROUP_IOSCHED
> unsigned short iocg_id;
> + dev_t dev;
> + /* How many times this group has been removed from active tree */
> + unsigned long dequeue;
> #endif
> };
>
> Index: linux14/block/elevator-fq.c
> ===================================================================
> --- linux14.orig/block/elevator-fq.c 2009-05-13 11:40:53.000000000 -0400
> +++ linux14/block/elevator-fq.c 2009-05-13 11:40:57.000000000 -0400
> @@ -12,6 +12,7 @@
> #include "elevator-fq.h"
> #include <linux/blktrace_api.h>
> #include <linux/biotrack.h>
> +#include <linux/seq_file.h>
>
> /* Values taken from cfq */
> const int elv_slice_sync = HZ / 10;
> @@ -758,6 +759,18 @@ int __bfq_deactivate_entity(struct io_en
> BUG_ON(sd->active_entity == entity);
> BUG_ON(sd->next_active == entity);
>
> +#ifdef CONFIG_DEBUG_GROUP_IOSCHED
> + {
> + struct io_group *iog = io_entity_to_iog(entity);
> + /*
> + * Keep track of how many times a group has been removed
> + * from active tree because it did not have any active
> + * backlogged ioq under it
> + */
> + if (iog)
> + iog->dequeue++;
> + }
> +#endif
> return ret;
> }
>
> @@ -1126,90 +1139,103 @@ STORE_FUNCTION(weight, 0, WEIGHT_MAX);
> STORE_FUNCTION(ioprio_class, IOPRIO_CLASS_RT, IOPRIO_CLASS_IDLE);
> #undef STORE_FUNCTION
>
> -/*
> - * traverse through all the io_groups associated with this cgroup and calculate
> - * the aggr disk time received by all the groups on respective disks.
> - */
> -static u64 calculate_aggr_disk_time(struct io_cgroup *iocg)
> +static int io_cgroup_disk_time_read(struct cgroup *cgroup,
> + struct cftype *cftype, struct seq_file *m)
> {
> + struct io_cgroup *iocg;
> struct io_group *iog;
> struct hlist_node *n;
> - u64 disk_time = 0;
> +
> + if (!cgroup_lock_live_group(cgroup))
> + return -ENODEV;
> +
> + iocg = cgroup_to_io_cgroup(cgroup);
>
> rcu_read_lock();
> + spin_lock_irq(&iocg->lock);
> hlist_for_each_entry_rcu(iog, n, &iocg->group_data, group_node) {
> /*
> * There might be groups which are not functional and
> * waiting to be reclaimed upon cgoup deletion.
> */
> - if (rcu_dereference(iog->key))
> - disk_time += iog->entity.total_service;
> + if (rcu_dereference(iog->key)) {
> + seq_printf(m, "%u %u %lu\n", MAJOR(iog->dev),
> + MINOR(iog->dev),
> + iog->entity.total_service);
Hi Vivek,
I think it's easier for users if device name is also shown here.
> + }
> }
> + spin_unlock_irq(&iocg->lock);
> rcu_read_unlock();
>
> - return disk_time;
> + cgroup_unlock();
> +
> + return 0;
> }
>
--
Regards
Gui Jianfeng
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