| Message ID | 20170712165400.GA9696@localhost.didichuxing.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 07/12/2017 10:54 AM, weiping zhang wrote: > A mapping show as following: > > hctx cpus > hctx0 0 1 > hctx1 2 > hctx2 3 > hctx3 4 5 We already have that information in the /sys/block/<dev>/mq/X/cpu_list where X is the hardware queue number. Why do we need it in debugfs as well, presented differently?
On Wed, Jul 12, 2017 at 10:57:37AM -0600, Jens Axboe wrote: > On 07/12/2017 10:54 AM, weiping zhang wrote: > > A mapping show as following: > > > > hctx cpus > > hctx0 0 1 > > hctx1 2 > > hctx2 3 > > hctx3 4 5 > > We already have that information in the /sys/block/<dev>/mq/X/cpu_list > > where X is the hardware queue number. Why do we need it in debugfs as > well, presented differently? this arribute give a more obviously showing, only by 1 "cat" command. /sys/bloc/<dev>/mq/X/cpu_list not easy get mapping for all hctx by 1 command. also /sys/kernel/debug/block/xxx/hctxN/cpuX can export that info, but these two methods both not obviously.
On 07/12/2017 11:13 AM, weiping zhang wrote: > On Wed, Jul 12, 2017 at 10:57:37AM -0600, Jens Axboe wrote: >> On 07/12/2017 10:54 AM, weiping zhang wrote: >>> A mapping show as following: >>> >>> hctx cpus >>> hctx0 0 1 >>> hctx1 2 >>> hctx2 3 >>> hctx3 4 5 >> >> We already have that information in the /sys/block/<dev>/mq/X/cpu_list >> >> where X is the hardware queue number. Why do we need it in debugfs as >> well, presented differently? > > this arribute give a more obviously showing, only by 1 "cat" command. > /sys/bloc/<dev>/mq/X/cpu_list not easy get mapping for all hctx by 1 > command. > also /sys/kernel/debug/block/xxx/hctxN/cpuX can export that info, but > these two methods both not obviously. The point is the information is there, and I'm sure most people can work out the shell logic to collect this info. I see zero benefit to adding this to debugfs.
On Wed, Jul 12, 2017 at 11:25:12AM -0600, Jens Axboe wrote: > On 07/12/2017 11:13 AM, weiping zhang wrote: > > On Wed, Jul 12, 2017 at 10:57:37AM -0600, Jens Axboe wrote: > >> On 07/12/2017 10:54 AM, weiping zhang wrote: > >>> A mapping show as following: > >>> > >>> hctx cpus > >>> hctx0 0 1 > >>> hctx1 2 > >>> hctx2 3 > >>> hctx3 4 5 > >> > >> We already have that information in the /sys/block/<dev>/mq/X/cpu_list > >> > >> where X is the hardware queue number. Why do we need it in debugfs as > >> well, presented differently? > > > > this arribute give a more obviously showing, only by 1 "cat" command. > > /sys/bloc/<dev>/mq/X/cpu_list not easy get mapping for all hctx by 1 > > command. > > also /sys/kernel/debug/block/xxx/hctxN/cpuX can export that info, but > > these two methods both not obviously. > > The point is the information is there, and I'm sure most people can > work out the shell logic to collect this info. I see zero benefit to > adding this to debugfs. > Hi Jens, It seems no other people wanna this patch, please skip it, thanks for your replay ^_^. -- weiping
diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c index 9ebc294..a311d5a 100644 --- a/block/blk-mq-debugfs.c +++ b/block/blk-mq-debugfs.c @@ -175,6 +175,23 @@ static int queue_poll_stat_show(void *data, struct seq_file *m) return 0; } +static int queue_mapping_show(void *data, struct seq_file *m) +{ + struct request_queue *q = data; + struct blk_mq_hw_ctx *hctx; + struct blk_mq_ctx *ctx; + int i, j; + + seq_puts(m, "hctx\t\tcpus\n"); + queue_for_each_hw_ctx(q, hctx, i) { + seq_printf(m, "hctx%u\t\t", hctx->queue_num); + hctx_for_each_ctx(hctx, ctx, j) + seq_printf(m, "%3u ", ctx->cpu); + seq_puts(m, "\n"); + } + return 0; +} + #define HCTX_STATE_NAME(name) [BLK_MQ_S_##name] = #name static const char *const hctx_state_name[] = { HCTX_STATE_NAME(STOPPED), @@ -754,6 +771,7 @@ static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = { {"requeue_list", 0400, .seq_ops = &queue_requeue_list_seq_ops}, {"state", 0600, queue_state_show, queue_state_write}, {"write_hints", 0600, queue_write_hint_show, queue_write_hint_store}, + {"mapping", 0400, queue_mapping_show}, {}, };
A mapping show as following: hctx cpus hctx0 0 1 hctx1 2 hctx2 3 hctx3 4 5 Signed-off-by: weiping zhang <zhangweiping@didichuxing.com> --- block/blk-mq-debugfs.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)