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SN6PR10MB2943.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 27 May 2021 15:13:51.2908 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: ykWbPqu786C1Sc92HA/SmoXTiJaYcMgQ1G1OTYA8TsrWyH6gDsK6gAElgUpzEk7JqEwFI+doENSAUzh/vGyPmdZKAzfmRrJOa6mraxtb5IU= X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN6PR10MB3022 X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=9996 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 malwarescore=0 spamscore=0 adultscore=0 bulkscore=0 mlxlogscore=999 suspectscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104190000 definitions=main-2105270100 X-Proofpoint-ORIG-GUID: G_DHKSP3vsMPnoVyN7CF7cylZeGoyYIU X-Proofpoint-GUID: G_DHKSP3vsMPnoVyN7CF7cylZeGoyYIU X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=9996 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 spamscore=0 mlxscore=0 malwarescore=0 mlxlogscore=999 lowpriorityscore=0 impostorscore=0 adultscore=0 phishscore=0 priorityscore=1501 clxscore=1011 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104190000 definitions=main-2105270100 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 5/26/21 8:01 PM, Bart Van Assche wrote: > Make the code easier to read by adding more comments. > > Cc: Damien Le Moal > Cc: Christoph Hellwig > Cc: Ming Lei > Signed-off-by: Bart Van Assche > --- > block/mq-deadline.c | 18 ++++++++++++++++++ > 1 file changed, 18 insertions(+) > > diff --git a/block/mq-deadline.c b/block/mq-deadline.c > index 8eea2cbf2bf4..64cabbc157ea 100644 > --- a/block/mq-deadline.c > +++ b/block/mq-deadline.c > @@ -139,6 +139,9 @@ static void dd_request_merged(struct request_queue *q, struct request *req, > } > } > > +/* > + * Callback function that is invoked after @next has been merged into @req. > + */ > static void dd_merged_requests(struct request_queue *q, struct request *req, > struct request *next) > { > @@ -375,6 +378,8 @@ static struct request *__dd_dispatch_request(struct deadline_data *dd) > } > > /* > + * Called from blk_mq_run_hw_queue() -> __blk_mq_sched_dispatch_requests(). > + * > * One confusing aspect here is that we get called for a specific > * hardware queue, but we may return a request that is for a > * different hardware queue. This is because mq-deadline has shared > @@ -438,6 +443,10 @@ static int dd_init_queue(struct request_queue *q, struct elevator_type *e) > return 0; > } > > +/* > + * Try to merge @bio into an existing request. If @bio has been merged into > + * an existing request, store the pointer to that request into *@rq. > + */ > static int dd_request_merge(struct request_queue *q, struct request **rq, > struct bio *bio) > { > @@ -461,6 +470,10 @@ static int dd_request_merge(struct request_queue *q, struct request **rq, > return ELEVATOR_NO_MERGE; > } > > +/* > + * Attempt to merge a bio into an existing request. This function is called > + * before @bio is associated with a request. > + */ > static bool dd_bio_merge(struct request_queue *q, struct bio *bio, > unsigned int nr_segs) > { > @@ -518,6 +531,9 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, > } > } > > +/* > + * Called from blk_mq_sched_insert_request() or blk_mq_sched_insert_requests(). > + */ > static void dd_insert_requests(struct blk_mq_hw_ctx *hctx, > struct list_head *list, bool at_head) > { > @@ -544,6 +560,8 @@ static void dd_prepare_request(struct request *rq) > } > > /* > + * Callback function called from inside blk_mq_free_request(). > + * > * For zoned block devices, write unlock the target zone of > * completed write requests. Do this while holding the zone lock > * spinlock so that the zone is never unlocked while deadline_fifo_request() > Reviewed-by: Himanshu Madhani -- Himanshu Madhani Oracle Linux Engineering