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authorjimharris <jimharris@FreeBSD.org>2015-05-14 21:27:31 +0000
committerjimharris <jimharris@FreeBSD.org>2015-05-14 21:27:31 +0000
commit701899b4c60bea7ac2e6131cebeb547762f23317 (patch)
treeea8b9ca6563a24db92f1b6ca3b0665c25fe8169d /sys
parent30e0f73c2f69f805f1c7381f9bcb0a03802f5038 (diff)
downloadFreeBSD-src-701899b4c60bea7ac2e6131cebeb547762f23317.zip
FreeBSD-src-701899b4c60bea7ac2e6131cebeb547762f23317.tar.gz
MFC r281280:
nvme: fall back to a smaller MSI-X vector allocation if necessary Previously, if per-CPU MSI-X vectors could not be allocated, nvme(4) would fall back to INTx with a single I/O queue pair. This change will still fall back to a single I/O queue pair, but allocate MSI-X vectors instead of reverting to INTx. Sponsored by: Intel
Diffstat (limited to 'sys')
-rw-r--r--sys/dev/nvme/nvme_ctrlr.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/sys/dev/nvme/nvme_ctrlr.c b/sys/dev/nvme/nvme_ctrlr.c
index cf3b3b2..6b0d6f3 100644
--- a/sys/dev/nvme/nvme_ctrlr.c
+++ b/sys/dev/nvme/nvme_ctrlr.c
@@ -1144,9 +1144,17 @@ nvme_ctrlr_construct(struct nvme_controller *ctrlr, device_t dev)
/* One vector per IO queue, plus one vector for admin queue. */
num_vectors = ctrlr->num_io_queues + 1;
- if (pci_msix_count(dev) < num_vectors) {
+ /*
+ * If we cannot even allocate 2 vectors (one for admin, one for
+ * I/O), then revert to INTx.
+ */
+ if (pci_msix_count(dev) < 2) {
ctrlr->msix_enabled = 0;
goto intx;
+ } else if (pci_msix_count(dev) < num_vectors) {
+ ctrlr->per_cpu_io_queues = FALSE;
+ ctrlr->num_io_queues = 1;
+ num_vectors = 2; /* one for admin, one for I/O */
}
if (pci_alloc_msix(dev, &num_vectors) != 0) {
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