From: John Garry <john.garry@huawei.com>
To: Hannes Reinecke <hare@suse.de>, <axboe@kernel.dk>,
<jejb@linux.ibm.com>, <martin.petersen@oracle.com>,
<don.brace@microsemi.com>, <kashyap.desai@broadcom.com>,
<sumit.saxena@broadcom.com>, <ming.lei@redhat.com>,
<bvanassche@acm.org>, <hare@suse.com>, <hch@lst.de>,
<shivasharan.srikanteshwara@broadcom.com>
Cc: <linux-block@vger.kernel.org>, <linux-scsi@vger.kernel.org>,
<esc.storagedev@microsemi.com>, <chenxiang66@hisilicon.com>,
<megaraidlinux.pdl@broadcom.com>
Subject: Re: [PATCH RFC v7 07/12] blk-mq: Add support in hctx_tags_bitmap_show() for a shared sbitmap
Date: Mon, 13 Jul 2020 10:41:58 +0100 [thread overview]
Message-ID: <2de767d0-d472-9101-f805-68194687279a@huawei.com> (raw)
In-Reply-To: <7ed6ccf1-6ad9-1df7-f55d-4ed6cac1e08d@suse.de>
On 12/06/2020 07:06, Hannes Reinecke wrote:
>>>>
>>>> +out:
>>>> + sbitmap_free(&shared_sb);
>>>> + return res;
>>>> +}
>>>> +
>>>> static int hctx_tags_bitmap_show(void *data, struct seq_file *m)
>>>> {
>>>> struct blk_mq_hw_ctx *hctx = data;
>>>> @@ -823,6 +884,7 @@ static const struct blk_mq_debugfs_attr
>>>> blk_mq_debugfs_hctx_shared_sbitmap_attrs
>>>> {"busy", 0400, hctx_busy_show},
>>>> {"ctx_map", 0400, hctx_ctx_map_show},
>>>> {"tags", 0400, hctx_tags_show},
>>>> + {"tags_bitmap", 0400, hctx_tags_shared_sbitmap_bitmap_show},
>>>> {"sched_tags", 0400, hctx_sched_tags_show},
>>>> {"sched_tags_bitmap", 0400, hctx_sched_tags_bitmap_show},
>>>> {"io_poll", 0600, hctx_io_poll_show, hctx_io_poll_write},
>>>>
>>> Ah, right. Here it is.
>>>
>>> But I don't get it; why do we have to allocate a temporary bitmap and
>>> can't walk the existing shared sbitmap?
>>
Just coming back to this now...
>> For the bitmap dump - sbitmap_bitmap_show() - it is passed a struct
>> sbitmap *. So we have to filter into a temp per-hctx struct sbitmap.
>> We could change sbitmap_bitmap_show() to accept a filter iterator -
>> which I think you're getting at - but I am not sure it's worth the
>> change. Or else use the allocated sbitmap for the hctx, as above*, but
>> I may be remove that (see 4/12 response).
>>
> Yes, I do think I would prefer updating sbitmap_bitmap_show() to accept
> a filter. Especially as Ming Lei has now updated the tag iterators to
> accept a filter, too, so it should be an easy change.
Can you please explain how you would use an iterator here?
In fact, I am half thinking of dropping this patch entirely.
So I feel that current behavior is a little strange, as some may expect
/sys/kernel/debug/block/sdX/hctxY/tags_bitmap would only show tags for
hctxY for sdX, while it is for hctxY for all queues. Same for
/sys/kernel/debug/block/sdX/hctxY/tags
And then, for what we have in this patch:
static void hctx_filter_sb(struct sbitmap *sb, struct blk_mq_hw_ctx *hctx)
{
struct hctx_sb_data hctx_sb_data = { .sb = sb, .hctx = hctx };
blk_mq_queue_tag_busy_iter(hctx->queue, hctx_filter_fn, &hctx_sb_data);
}
This will give tags only for this queue. So not the same. So I feel it's
better to change current behavior (so consistent) or change neither. And
changing current behavior would also mean we need to change what we show
in /sys/kernel/debug/block/sdX/hctxY/tags, and that looks troublesome also.
Opinion?
Thanks,
John
next prev parent reply other threads:[~2020-07-13 9:43 UTC|newest]
Thread overview: 123+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-10 17:29 [PATCH RFC v7 00/12] blk-mq/scsi: Provide hostwide shared tags for SCSI HBAs John Garry
2020-06-10 17:29 ` [PATCH RFC v7 01/12] blk-mq: rename BLK_MQ_F_TAG_SHARED as BLK_MQ_F_TAG_QUEUE_SHARED John Garry
2020-06-10 17:29 ` [PATCH RFC v7 02/12] blk-mq: rename blk_mq_update_tag_set_depth() John Garry
2020-06-11 2:57 ` Ming Lei
2020-06-11 8:26 ` John Garry
2020-06-23 11:25 ` John Garry
2020-06-23 14:23 ` Hannes Reinecke
2020-06-24 8:13 ` Kashyap Desai
2020-06-29 16:18 ` John Garry
2020-08-10 16:51 ` Kashyap Desai
2020-08-11 8:01 ` John Garry
2020-08-11 16:34 ` Kashyap Desai
2020-06-10 17:29 ` [PATCH RFC v7 03/12] blk-mq: Use pointers for blk_mq_tags bitmap tags John Garry
2020-06-10 17:29 ` [PATCH RFC v7 04/12] blk-mq: Facilitate a shared sbitmap per tagset John Garry
2020-06-11 3:37 ` Ming Lei
2020-06-11 10:09 ` John Garry
2020-06-10 17:29 ` [PATCH RFC v7 05/12] blk-mq: Record nr_active_requests per queue for when using shared sbitmap John Garry
2020-06-11 4:04 ` Ming Lei
2020-06-11 10:22 ` John Garry
2020-06-10 17:29 ` [PATCH RFC v7 06/12] blk-mq: Record active_queues_shared_sbitmap per tag_set " John Garry
2020-06-11 13:16 ` Hannes Reinecke
2020-06-11 14:22 ` John Garry
2020-06-10 17:29 ` [PATCH RFC v7 07/12] blk-mq: Add support in hctx_tags_bitmap_show() for a " John Garry
2020-06-11 13:19 ` Hannes Reinecke
2020-06-11 14:33 ` John Garry
2020-06-12 6:06 ` Hannes Reinecke
2020-06-29 15:32 ` About sbitmap_bitmap_show() and cleared bits (was Re: [PATCH RFC v7 07/12] blk-mq: Add support in hctx_tags_bitmap_show() for a shared sbitmap) John Garry
2020-06-30 6:33 ` Hannes Reinecke
2020-06-30 7:30 ` John Garry
2020-06-30 11:36 ` John Garry
2020-06-30 14:55 ` Bart Van Assche
2020-07-13 9:41 ` John Garry [this message]
2020-07-13 12:20 ` [PATCH RFC v7 07/12] blk-mq: Add support in hctx_tags_bitmap_show() for a shared sbitmap Hannes Reinecke
2020-06-10 17:29 ` [PATCH RFC v7 08/12] scsi: Add template flag 'host_tagset' John Garry
2020-06-10 17:29 ` [PATCH RFC v7 09/12] scsi: hisi_sas: Switch v3 hw to MQ John Garry
2020-06-10 17:29 ` [PATCH RFC v7 10/12] megaraid_sas: switch fusion adapters " John Garry
2020-07-02 10:23 ` Kashyap Desai
2020-07-06 8:23 ` John Garry
2020-07-06 8:45 ` Hannes Reinecke
2020-07-06 9:26 ` John Garry
2020-07-06 9:40 ` Hannes Reinecke
2020-07-06 19:19 ` Kashyap Desai
2020-07-07 7:58 ` John Garry
2020-07-07 14:45 ` Kashyap Desai
2020-07-07 16:17 ` John Garry
2020-07-09 19:01 ` Kashyap Desai
2020-07-10 8:10 ` John Garry
2020-07-13 7:55 ` Kashyap Desai
2020-07-13 8:42 ` John Garry
2020-07-19 19:07 ` Kashyap Desai
2020-07-20 7:23 ` Kashyap Desai
2020-07-20 9:18 ` John Garry
2020-07-21 1:13 ` Ming Lei
2020-07-21 6:53 ` Kashyap Desai
2020-07-22 4:12 ` Ming Lei
2020-07-22 5:30 ` Kashyap Desai
2020-07-22 8:04 ` Ming Lei
2020-07-22 9:32 ` John Garry
2020-07-23 14:07 ` Ming Lei
2020-07-23 17:29 ` John Garry
2020-07-24 2:47 ` Ming Lei
2020-07-28 7:54 ` John Garry
2020-07-28 8:45 ` Ming Lei
2020-07-29 5:25 ` Kashyap Desai
2020-07-29 15:36 ` Ming Lei
2020-07-29 18:31 ` Kashyap Desai
2020-08-04 8:36 ` Ming Lei
2020-08-04 9:27 ` Kashyap Desai
2020-08-05 8:40 ` Ming Lei
2020-08-06 10:25 ` Kashyap Desai
2020-08-06 13:38 ` Ming Lei
2020-08-06 14:37 ` Kashyap Desai
2020-08-06 15:29 ` Ming Lei
2020-08-08 19:05 ` Kashyap Desai
2020-08-09 2:16 ` Ming Lei
2020-08-10 16:38 ` Kashyap Desai
2020-08-11 8:09 ` John Garry
2020-08-04 17:00 ` John Garry
2020-08-05 2:56 ` Ming Lei
2020-07-28 8:01 ` Kashyap Desai
2020-07-08 11:31 ` John Garry
2020-06-10 17:29 ` [PATCH RFC v7 11/12] smartpqi: enable host tagset John Garry
2020-07-14 13:16 ` John Garry
2020-07-14 13:31 ` John Garry
2020-07-14 18:16 ` Don.Brace
2020-07-15 7:28 ` John Garry
2020-07-14 14:02 ` Hannes Reinecke
2020-08-18 8:33 ` John Garry
2020-06-10 17:29 ` [PATCH RFC v7 12/12] hpsa: enable host_tagset and switch to MQ John Garry
2020-07-14 7:37 ` John Garry
2020-07-14 7:41 ` Hannes Reinecke
2020-07-14 7:52 ` John Garry
2020-07-14 8:06 ` Ming Lei
2020-07-14 9:53 ` John Garry
2020-07-14 10:14 ` Ming Lei
2020-07-14 10:43 ` Hannes Reinecke
2020-07-14 10:19 ` Hannes Reinecke
2020-07-14 10:35 ` John Garry
2020-07-14 10:44 ` Ming Lei
2020-07-14 10:52 ` John Garry
2020-07-14 12:04 ` Ming Lei
2020-08-03 20:39 ` Don.Brace
2020-08-04 9:27 ` John Garry
2020-08-04 15:18 ` Don.Brace
2020-08-05 11:21 ` John Garry
2020-08-14 21:04 ` Don.Brace
2020-08-17 8:00 ` John Garry
2020-08-17 18:39 ` Don.Brace
2020-08-18 7:14 ` Hannes Reinecke
2020-07-16 16:14 ` Don.Brace
2020-07-16 19:45 ` Don.Brace
2020-07-17 10:11 ` John Garry
2020-06-11 3:07 ` [PATCH RFC v7 00/12] blk-mq/scsi: Provide hostwide shared tags for SCSI HBAs Ming Lei
2020-06-11 9:35 ` John Garry
2020-06-12 18:47 ` Kashyap Desai
2020-06-15 2:13 ` Ming Lei
2020-06-15 6:57 ` Kashyap Desai
2020-06-16 1:00 ` Ming Lei
2020-06-17 11:26 ` Kashyap Desai
2020-06-22 6:24 ` Hannes Reinecke
2020-06-23 0:55 ` Ming Lei
2020-06-23 11:50 ` Kashyap Desai
2020-06-23 12:11 ` Kashyap Desai
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