Revision 1978f30a87732d4d9072a20abeded9fe17884f1b authored by Dongli Zhang on 27 March 2019, 10:36:35 UTC, committed by Jens Axboe on 10 April 2019, 14:18:25 UTC
When tag_set->nr_maps is 1, the block layer limits the number of hw queues
by nr_cpu_ids. No matter how many hw queues are used by virtio-scsi, as it
has (tag_set->nr_maps == 1), it can use at most nr_cpu_ids hw queues.

In addition, specifically for pci scenario, when the 'num_queues' specified
by qemu is more than maxcpus, virtio-scsi would not be able to allocate
more than maxcpus vectors in order to have a vector for each queue. As a
result, it falls back into MSI-X with one vector for config and one shared
for queues.

Considering above reasons, this patch limits the number of hw queues used
by virtio-scsi by nr_cpu_ids.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
1 parent bf348f9
History
File Mode Size
Kconfig -rw-r--r-- 625 bytes
Makefile -rw-r--r-- 248 bytes
balloc.c -rw-r--r-- 18.1 KB
dir.c -rw-r--r-- 5.2 KB
directory.c -rw-r--r-- 5.8 KB
ecma_167.h -rw-r--r-- 21.3 KB
file.c -rw-r--r-- 7.3 KB
ialloc.c -rw-r--r-- 3.5 KB
inode.c -rw-r--r-- 65.1 KB
lowlevel.c -rw-r--r-- 1.6 KB
misc.c -rw-r--r-- 7.7 KB
namei.c -rw-r--r-- 34.3 KB
osta_udf.h -rw-r--r-- 7.9 KB
partition.c -rw-r--r-- 8.7 KB
super.c -rw-r--r-- 65.6 KB
symlink.c -rw-r--r-- 4.2 KB
truncate.c -rw-r--r-- 7.9 KB
udf_i.h -rw-r--r-- 1.7 KB
udf_sb.h -rw-r--r-- 4.1 KB
udfdecl.h -rw-r--r-- 8.8 KB
udfend.h -rw-r--r-- 1.6 KB
udftime.c -rw-r--r-- 3.2 KB
unicode.c -rw-r--r-- 9.2 KB

back to top