Date: Wed, 8 Apr 2015 21:46:19 +0000 (UTC) From: Jim Harris <jimharris@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r281280 - head/sys/dev/nvme Message-ID: <201504082146.t38LkJ9s058300@svn.freebsd.org>
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Author: jimharris Date: Wed Apr 8 21:46:18 2015 New Revision: 281280 URL: https://svnweb.freebsd.org/changeset/base/281280 Log: 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. MFC after: 1 week Sponsored by: Intel Modified: head/sys/dev/nvme/nvme_ctrlr.c Modified: head/sys/dev/nvme/nvme_ctrlr.c ============================================================================== --- head/sys/dev/nvme/nvme_ctrlr.c Wed Apr 8 21:10:13 2015 (r281279) +++ head/sys/dev/nvme/nvme_ctrlr.c Wed Apr 8 21:46:18 2015 (r281280) @@ -1144,9 +1144,17 @@ nvme_ctrlr_construct(struct nvme_control /* 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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