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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Dongli Zhang <dongli.zhang@oracle.com>,
	Jens Axboe <axboe@kernel.dk>, Sasha Levin <sashal@kernel.org>,
	virtualization@lists.linux-foundation.org,
	linux-block@vger.kernel.org
Subject: [PATCH AUTOSEL 4.14 26/32] virtio-blk: limit number of hw queues by nr_cpu_ids
Date: Fri, 26 Apr 2019 21:42:17 -0400	[thread overview]
Message-ID: <20190427014224.8274-26-sashal@kernel.org> (raw)
In-Reply-To: <20190427014224.8274-1-sashal@kernel.org>

From: Dongli Zhang <dongli.zhang@oracle.com>

[ Upstream commit bf348f9b78d413e75bb079462751a1d86b6de36c ]

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-blk, 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-blk 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-blk 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: Sasha Levin <sashal@kernel.org>
---
 drivers/block/virtio_blk.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 68846897d213..8767401f75e0 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -437,6 +437,8 @@ static int init_vq(struct virtio_blk *vblk)
 	if (err)
 		num_vqs = 1;
 
+	num_vqs = min_t(unsigned int, nr_cpu_ids, num_vqs);
+
 	vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL);
 	if (!vblk->vqs)
 		return -ENOMEM;
-- 
2.19.1


  parent reply	other threads:[~2019-04-27  1:43 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-27  1:41 [PATCH AUTOSEL 4.14 01/32] ASoC: hdmi-codec: fix S/PDIF DAI Sasha Levin
2019-04-27  1:41 ` [PATCH AUTOSEL 4.14 02/32] ASoC: ab8500: Mark expected switch fall-through Sasha Levin
2019-04-27  1:41 ` [PATCH AUTOSEL 4.14 03/32] ASoC:soc-pcm:fix a codec fixup issue in TDM case Sasha Levin
2019-04-27  1:41 ` [PATCH AUTOSEL 4.14 04/32] ASoC: nau8824: fix the issue of the widget with prefix name Sasha Levin
2019-04-27  1:41 ` [PATCH AUTOSEL 4.14 05/32] ASoC: nau8810: fix the issue of widget with prefixed name Sasha Levin
2019-04-27  1:41 ` [PATCH AUTOSEL 4.14 06/32] ASoC: samsung: odroid: Fix clock configuration for 44100 sample rate Sasha Levin
2019-04-27  1:41 ` [PATCH AUTOSEL 4.14 07/32] ASoC: wm_adsp: Add locking to wm_adsp2_bus_error Sasha Levin
2019-04-27  1:41 ` [PATCH AUTOSEL 4.14 08/32] ASoC: cs4270: Set auto-increment bit for register writes Sasha Levin
2019-04-27  1:42 ` [PATCH AUTOSEL 4.14 09/32] IB/hfi1: Eliminate opcode tests on mr deref Sasha Levin
2019-04-27  1:42 ` [PATCH AUTOSEL 4.14 10/32] MIPS: KGDB: fix kgdb support for SMP platforms Sasha Levin
2019-04-27  1:42 ` [PATCH AUTOSEL 4.14 11/32] ASoC: tlv320aic32x4: Fix Common Pins Sasha Levin
2019-04-27  1:42 ` [PATCH AUTOSEL 4.14 12/32] drm/mediatek: Fix an error code in mtk_hdmi_dt_parse_pdata() Sasha Levin
2019-04-27  1:42 ` [PATCH AUTOSEL 4.14 13/32] perf/x86/intel: Fix handling of wakeup_events for multi-entry PEBS Sasha Levin
2019-04-27  1:42 ` [PATCH AUTOSEL 4.14 14/32] perf/x86/intel: Initialize TFA MSR Sasha Levin
2019-04-27  1:42 ` [PATCH AUTOSEL 4.14 15/32] linux/kernel.h: Use parentheses around argument in u64_to_user_ptr() Sasha Levin
2019-04-27  1:42 ` [PATCH AUTOSEL 4.14 16/32] xtensa: fix initialization of pt_regs::syscall in start_thread Sasha Levin
2019-04-27  1:42 ` [PATCH AUTOSEL 4.14 17/32] ASoC: rockchip: pdm: fix regmap_ops hang issue Sasha Levin
2019-04-27  1:42 ` [PATCH AUTOSEL 4.14 18/32] slab: fix a crash by reading /proc/slab_allocators Sasha Levin
2019-04-27  1:42 ` [PATCH AUTOSEL 4.14 19/32] ASoC: stm32: fix sai driver name initialisation Sasha Levin
2019-04-27  1:42 ` [PATCH AUTOSEL 4.14 20/32] virtio_pci: fix a NULL pointer reference in vp_del_vqs Sasha Levin
2019-04-27  1:42 ` [PATCH AUTOSEL 4.14 21/32] RDMA/vmw_pvrdma: Fix memory leak on pvrdma_pci_remove Sasha Levin
2019-04-27  1:42 ` [PATCH AUTOSEL 4.14 22/32] scsi: csiostor: fix missing data copy in csio_scsi_err_handler() Sasha Levin
2019-04-27  1:42 ` [PATCH AUTOSEL 4.14 23/32] drm/mediatek: fix possible object reference leak Sasha Levin
2019-04-27  1:42 ` [PATCH AUTOSEL 4.14 24/32] Bluetooth: btusb: request wake pin with NOAUTOEN Sasha Levin
2019-04-27  1:42 ` [PATCH AUTOSEL 4.14 25/32] ASoC: Intel: kbl: fix wrong number of channels Sasha Levin
2019-04-27  1:42 ` Sasha Levin [this message]
2019-04-27  1:42 ` [PATCH AUTOSEL 4.14 27/32] clk: x86: Add system specific quirk to mark clocks as critical Sasha Levin
2019-04-27  1:42 ` [PATCH AUTOSEL 4.14 28/32] platform/x86: pmc_atom: Drop __initconst on dmi table Sasha Levin
2019-04-27  1:42 ` [PATCH AUTOSEL 4.14 29/32] NFS: Forbid setting AF_INET6 to "struct sockaddr_in"->sin_family Sasha Levin
2019-04-27  1:42 ` [PATCH AUTOSEL 4.14 30/32] iommu/amd: Set exclusion range correctly Sasha Levin
2019-04-27  1:42 ` [PATCH AUTOSEL 4.14 31/32] mm: make page ref count overflow check tighter and more explicit Sasha Levin
2019-04-27  1:42 ` [PATCH AUTOSEL 4.14 32/32] mm: add 'try_get_page()' helper function Sasha Levin

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