| Message ID | 1499347489-10863-1-git-send-email-maxg@mellanox.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 07/06/2017 07:24 AM, Max Gurtovoy wrote: > In case we use shared tags feature, blk_mq_alloc_tag_set might fail > during module initialization. Check the return value and default to run > without shared tag set before continuing. Also move the tagset > initialization process after defining the amount of submition queues. Fail the load instead. For two reasons: 1) We could be loading to test this explicitly. null_blk isn't a regular driver, it's not like we're bringing up the system on this thing. Hence I feel it's more important that it loads with what we asked for, or not load at all. 2) If initializing one tag set fails, the unshared case will surely fail too.
On 7/6/2017 5:02 PM, Jens Axboe wrote: > On 07/06/2017 07:24 AM, Max Gurtovoy wrote: >> In case we use shared tags feature, blk_mq_alloc_tag_set might fail >> during module initialization. Check the return value and default to run >> without shared tag set before continuing. Also move the tagset >> initialization process after defining the amount of submition queues. > > Fail the load instead. For two reasons: > > 1) We could be loading to test this explicitly. null_blk isn't a regular > driver, it's not like we're bringing up the system on this thing. > Hence I feel it's more important that it loads with what we asked for, > or not load at all. > > 2) If initializing one tag set fails, the unshared case will surely > fail too. > Ok. I'll send V2 version soon.
diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c index 71f4422..0b7e7e1 100644 --- a/drivers/block/null_blk.c +++ b/drivers/block/null_blk.c @@ -844,9 +844,6 @@ static int __init null_init(void) queue_mode = NULL_Q_MQ; } - if (queue_mode == NULL_Q_MQ && shared_tags) - null_init_tag_set(&tag_set); - if (queue_mode == NULL_Q_MQ && use_per_node_hctx) { if (submit_queues < nr_online_nodes) { pr_warn("null_blk: submit_queues param is set to %u.", @@ -858,6 +855,15 @@ static int __init null_init(void) else if (!submit_queues) submit_queues = 1; + if (queue_mode == NULL_Q_MQ && shared_tags) { + ret = null_init_tag_set(&tag_set); + if (ret) { + pr_warn("null_blk: Can't use shared tags %d\n", ret); + pr_warn("null_blk: defaults to non shared tags\n"); + shared_tags = false; + } + } + mutex_init(&lock); null_major = register_blkdev(0, "nullb");
In case we use shared tags feature, blk_mq_alloc_tag_set might fail during module initialization. Check the return value and default to run without shared tag set before continuing. Also move the tagset initialization process after defining the amount of submition queues. Signed-off-by: Max Gurtovoy <maxg@mellanox.com> --- drivers/block/null_blk.c | 12 +++++++++--- 1 files changed, 9 insertions(+), 3 deletions(-)