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block: convert REQ_ATOM_COMPLETE to stealing rq->__deadline bit

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We only have one atomic flag left. Instead of using an entire
unsigned long for that, steal the bottom bit of the deadline
field that we already reserved.

Remove ->atomic_flags, since it's now unused.

Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2018-01-10 11:34:25 -07:00
parent 0a72e7f449
commit e14575b3d4
5 changed files with 12 additions and 22 deletions
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2
block/blk-core.c
View File

@ -2853,7 +2853,7 @@ void blk_start_request(struct request *req)
wbt_issue(req->q->rq_wb, &req->issue_stat);
}
BUG_ON(test_bit(REQ_ATOM_COMPLETE, &req->atomic_flags));
BUG_ON(blk_rq_is_complete(req));
blk_add_timer(req);
}
EXPORT_SYMBOL(blk_start_request);

9
block/blk-mq-debugfs.c
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@ -294,12 +294,6 @@ static const char *const rqf_name[] = {
};
#undef RQF_NAME
#define RQAF_NAME(name) [REQ_ATOM_##name] = #name
static const char *const rqaf_name[] = {
RQAF_NAME(COMPLETE),
};
#undef RQAF_NAME
int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq)
{
const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
@ -316,8 +310,7 @@ int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq)
seq_puts(m, ", .rq_flags=");
blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,
ARRAY_SIZE(rqf_name));
seq_puts(m, ", .atomic_flags=");
blk_flags_show(m, rq->atomic_flags, rqaf_name, ARRAY_SIZE(rqaf_name));
seq_printf(m, ", complete=%d", blk_rq_is_complete(rq));
seq_printf(m, ", .tag=%d, .internal_tag=%d", rq->tag,
rq->internal_tag);
if (mq_ops->show_rq)

2
block/blk-mq.c
View File

@ -294,7 +294,6 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
rq->rq_flags |= RQF_PREEMPT;
if (blk_queue_io_stat(data->q))
rq->rq_flags |= RQF_IO_STAT;
/* do not touch atomic flags, it needs atomic ops against the timer */
rq->cpu = -1;
INIT_HLIST_NODE(&rq->hash);
RB_CLEAR_NODE(&rq->rb_node);
@ -313,6 +312,7 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
rq->special = NULL;
/* tag was already set */
rq->extra_len = 0;
rq->__deadline = 0;
INIT_LIST_HEAD(&rq->timeout_list);
rq->timeout = 0;

19
block/blk.h
View File

@ -119,25 +119,24 @@ void blk_account_io_start(struct request *req, bool new_io);
void blk_account_io_completion(struct request *req, unsigned int bytes);
void blk_account_io_done(struct request *req);
/*
* Internal atomic flags for request handling
*/
enum rq_atomic_flags {
REQ_ATOM_COMPLETE = 0,
};
/*
* EH timer and IO completion will both attempt to 'grab' the request, make
* sure that only one of them succeeds
* sure that only one of them succeeds. Steal the bottom bit of the
* __deadline field for this.
*/
static inline int blk_mark_rq_complete(struct request *rq)
{
return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
return test_and_set_bit(0, &rq->__deadline);
}
static inline void blk_clear_rq_complete(struct request *rq)
{
clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
clear_bit(0, &rq->__deadline);
}
static inline bool blk_rq_is_complete(struct request *rq)
{
return test_bit(0, &rq->__deadline);
}
/*

2
include/linux/blkdev.h
View File

@ -156,8 +156,6 @@ struct request {
int internal_tag;
unsigned long atomic_flags;
/* the following two fields are internal, NEVER access directly */
unsigned int __data_len; /* total data len */
int tag;