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| author | Dongli Zhang <dongli.zhang@oracle.com> | 2019-03-27 18:36:35 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-11-28 16:45:46 +0000 |
| commit | 0101448977efbeb2e35162d28ff8ec7bff2e5855 (patch) | |
| tree | 2a580d6e766125ac14b929e86327371626beccba /tools/perf/scripts/python/stackcollapse.py | |
| parent | 62a78cf03383630f21869ac0a1333389235d556d (diff) | |
scsi: virtio_scsi: limit number of hw queues by nr_cpu_ids
commit 1978f30a87732d4d9072a20abeded9fe17884f1b upstream.
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>
Signed-off-by: Kunkun Jiang <jiangkunkun@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'tools/perf/scripts/python/stackcollapse.py')
0 files changed, 0 insertions, 0 deletions