From: Fam Zheng <zhengfeiran@bytedance.com>
To: linux-kernel@vger.kernel.org
Cc: axboe@kernel.dk, fam@euphon.net, paolo.valente@linaro.org,
duanxiongchun@bytedance.com, linux-block@vger.kernel.org,
tj@kernel.org, cgroups@vger.kernel.org,
zhangjiachen.jc@bytedance.com
Subject: [PATCH v2 3/3] bfq: Add per-device weight
Date: Mon, 5 Aug 2019 14:38:07 +0800 [thread overview]
Message-ID: <20190805063807.9494-4-zhengfeiran@bytedance.com> (raw)
In-Reply-To: <20190805063807.9494-1-zhengfeiran@bytedance.com>
Signed-off-by: Fam Zheng <zhengfeiran@bytedance.com>
---
block/bfq-cgroup.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++-------
block/bfq-iosched.h | 3 ++
2 files changed, 87 insertions(+), 11 deletions(-)
diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
index 28e5a9241237..de4fd8b725aa 100644
--- a/block/bfq-cgroup.c
+++ b/block/bfq-cgroup.c
@@ -904,7 +904,7 @@ void bfq_end_wr_async(struct bfq_data *bfqd)
bfq_end_wr_async_queues(bfqd, bfqd->root_group);
}
-static int bfq_io_show_weight(struct seq_file *sf, void *v)
+static int bfq_io_show_weight_legacy(struct seq_file *sf, void *v)
{
struct blkcg *blkcg = css_to_blkcg(seq_css(sf));
struct bfq_group_data *bfqgd = blkcg_to_bfqgd(blkcg);
@@ -918,8 +918,32 @@ static int bfq_io_show_weight(struct seq_file *sf, void *v)
return 0;
}
-static void bfq_group_set_weight(struct bfq_group *bfqg, u64 weight)
+static u64 bfqg_prfill_weight_device(struct seq_file *sf,
+ struct blkg_policy_data *pd, int off)
+{
+ struct bfq_group *bfqg = pd_to_bfqg(pd);
+
+ if (!bfqg->entity.dev_weight)
+ return 0;
+ return __blkg_prfill_u64(sf, pd, bfqg->entity.dev_weight);
+}
+
+static int bfq_io_show_weight(struct seq_file *sf, void *v)
+{
+ struct blkcg *blkcg = css_to_blkcg(seq_css(sf));
+ struct bfq_group_data *bfqgd = blkcg_to_bfqgd(blkcg);
+
+ seq_printf(sf, "default %u\n", bfqgd->weight);
+ blkcg_print_blkgs(sf, blkcg, bfqg_prfill_weight_device,
+ &blkcg_policy_bfq, 0, false);
+ return 0;
+}
+
+static void bfq_group_set_weight(struct bfq_group *bfqg, u64 weight, u64 dev_weight)
{
+ weight = dev_weight ?: weight;
+
+ bfqg->entity.dev_weight = dev_weight;
/*
* Setting the prio_changed flag of the entity
* to 1 with new_weight == weight would re-set
@@ -967,28 +991,71 @@ static int bfq_io_set_weight_legacy(struct cgroup_subsys_state *css,
struct bfq_group *bfqg = blkg_to_bfqg(blkg);
if (bfqg)
- bfq_group_set_weight(bfqg, val);
+ bfq_group_set_weight(bfqg, val, 0);
}
spin_unlock_irq(&blkcg->lock);
return ret;
}
-static ssize_t bfq_io_set_weight(struct kernfs_open_file *of,
- char *buf, size_t nbytes,
- loff_t off)
+static ssize_t bfq_io_set_device_weight(struct kernfs_open_file *of,
+ char *buf, size_t nbytes,
+ loff_t off)
{
- u64 weight;
- /* First unsigned long found in the file is used */
- int ret = kstrtoull(strim(buf), 0, &weight);
+ int ret;
+ struct blkg_conf_ctx ctx;
+ struct blkcg *blkcg = css_to_blkcg(of_css(of));
+ struct bfq_group *bfqg;
+ u64 v;
+ ret = blkg_conf_prep(blkcg, &blkcg_policy_bfq, buf, &ctx);
if (ret)
return ret;
- ret = bfq_io_set_weight_legacy(of_css(of), NULL, weight);
+ if (sscanf(ctx.body, "%llu", &v) == 1) {
+ /* require "default" on dfl */
+ ret = -ERANGE;
+ if (!v)
+ goto out;
+ } else if (!strcmp(strim(ctx.body), "default")) {
+ v = 0;
+ } else {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ bfqg = blkg_to_bfqg(ctx.blkg);
+
+ ret = -ERANGE;
+ if (!v || (v >= BFQ_MIN_WEIGHT && v <= BFQ_MAX_WEIGHT)) {
+ bfq_group_set_weight(bfqg, bfqg->entity.weight, v);
+ ret = 0;
+ }
+out:
+ blkg_conf_finish(&ctx);
return ret ?: nbytes;
}
+static ssize_t bfq_io_set_weight(struct kernfs_open_file *of,
+ char *buf, size_t nbytes,
+ loff_t off)
+{
+ char *endp;
+ int ret;
+ u64 v;
+
+ buf = strim(buf);
+
+ /* "WEIGHT" or "default WEIGHT" sets the default weight */
+ v = simple_strtoull(buf, &endp, 0);
+ if (*endp == '\0' || sscanf(buf, "default %llu", &v) == 1) {
+ ret = bfq_io_set_weight_legacy(of_css(of), NULL, v);
+ return ret ?: nbytes;
+ }
+
+ return bfq_io_set_device_weight(of, buf, nbytes, off);
+}
+
#ifdef CONFIG_BFQ_CGROUP_DEBUG
static int bfqg_print_stat(struct seq_file *sf, void *v)
{
@@ -1145,9 +1212,15 @@ struct cftype bfq_blkcg_legacy_files[] = {
{
.name = "bfq.weight",
.flags = CFTYPE_NOT_ON_ROOT,
- .seq_show = bfq_io_show_weight,
+ .seq_show = bfq_io_show_weight_legacy,
.write_u64 = bfq_io_set_weight_legacy,
},
+ {
+ .name = "bfq.weight_device",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .seq_show = bfq_io_show_weight,
+ .write = bfq_io_set_weight,
+ },
/* statistics, covers only the tasks in the bfqg */
{
diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h
index e80adf822bbe..5d1a519640f6 100644
--- a/block/bfq-iosched.h
+++ b/block/bfq-iosched.h
@@ -168,6 +168,9 @@ struct bfq_entity {
/* budget, used also to calculate F_i: F_i = S_i + @budget / @weight */
int budget;
+ /* device weight, if non-zero, it overrides the default weight of
+ * bfq_group_data */
+ int dev_weight;
/* weight of the queue */
int weight;
/* next weight if a change is in progress */
--
2.11.0
next prev parent reply other threads:[~2019-08-05 6:38 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-05 6:38 [PATCH v2 0/3] Implement BFQ per-device weight interface Fam Zheng
2019-08-05 6:38 ` [PATCH v2 1/3] bfq: Fix the missing barrier in __bfq_entity_update_weight_prio Fam Zheng
2019-08-05 6:38 ` [PATCH v2 2/3] bfq: Extract bfq_group_set_weight from bfq_io_set_weight_legacy Fam Zheng
2019-08-05 6:38 ` Fam Zheng [this message]
2019-08-21 15:44 ` [PATCH v2 3/3] bfq: Add per-device weight Tejun Heo
2019-08-26 6:36 ` Paolo Valente
2019-08-26 13:59 ` Jens Axboe
2019-08-28 3:50 ` Fam Zheng
2019-08-05 15:08 ` [PATCH v2 0/3] Implement BFQ per-device weight interface Paolo Valente
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190805063807.9494-4-zhengfeiran@bytedance.com \
--to=zhengfeiran@bytedance.com \
--cc=axboe@kernel.dk \
--cc=cgroups@vger.kernel.org \
--cc=duanxiongchun@bytedance.com \
--cc=fam@euphon.net \
--cc=linux-block@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=paolo.valente@linaro.org \
--cc=tj@kernel.org \
--cc=zhangjiachen.jc@bytedance.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).