Re: [PATCH 5/5] blk-mq: Drop 'reserved' member of busy_tag_iter_fn

From: Bart Van Assche
Date: Fri Jun 17 2022 - 12:33:20 EST


On 6/17/22 03:55, John Garry wrote:
We no longer use the 'reserved' member in for any iter function so it
^^^^^^
One of these two words probably should be removed.

diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index 2dcd738c6952..b8cc8b41553f 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -266,7 +266,6 @@ static bool bt_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data)
struct blk_mq_hw_ctx *hctx = iter_data->hctx;
struct request_queue *q = iter_data->q;
struct blk_mq_tag_set *set = q->tag_set;
- bool reserved = iter_data->reserved;
struct blk_mq_tags *tags;
struct request *rq;
bool ret = true;
@@ -276,7 +275,7 @@ static bool bt_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data)
else
tags = hctx->tags;
- if (!reserved)
+ if (!iter_data->reserved)
bitnr += tags->nr_reserved_tags;
/*
* We can hit rq == NULL here, because the tagging functions

Is the above change really necessary?

@@ -337,12 +336,11 @@ static bool bt_tags_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data)
{
struct bt_tags_iter_data *iter_data = data;
struct blk_mq_tags *tags = iter_data->tags;
- bool reserved = iter_data->flags & BT_TAG_ITER_RESERVED;
struct request *rq;
bool ret = true;
bool iter_static_rqs = !!(iter_data->flags & BT_TAG_ITER_STATIC_RQS);
- if (!reserved)
+ if (!(iter_data->flags & BT_TAG_ITER_RESERVED))
bitnr += tags->nr_reserved_tags;
/*

Same question here: is the above change really necessary?

Thanks,

Bart.