Re: [PATCH v3 1/4] scsi: scan: allocate sdev and starget on the NUMA node of the host adapter

Hannes Reinecke <[email protected]> Wed, 10 Jun 2026 08:00:30 +0200
Newsgroups org.kernel.vger.target-devel,dev.linux.lists.virtualization,org.kernel.vger.linux-block,org.kernel.vger.linux-hyperv,org.kernel.vger.linux-scsi,org.ozlabs.lists.linuxppc-dev,org.xenproject.lists.xen-devel
Message-ID <[email protected]>
On 6/9/26 14:18, Sumit Saxena wrote:
> From: James Rizzo <[email protected]>
> 
> When a host adapter is attached to a specific NUMA node, allocating
> scsi_device and scsi_target via kzalloc() may place them on a remote
> node.  All hot-path I/O accesses to these structures then cross the NUMA
> interconnect, adding latency and consuming inter-node bandwidth.
> 
> Use kzalloc_node() with dev_to_node(shost->dma_dev) so allocations land
> on the same node as the HBA, reducing cross-node traffic and improving
> I/O performance on NUMA systems.
> 
> Signed-off-by: James Rizzo <[email protected]>
> Signed-off-by: Sumit Saxena <[email protected]>
> ---
>   drivers/scsi/scsi_scan.c | 7 ++++---
>   1 file changed, 4 insertions(+), 3 deletions(-)
> 
Reviewed-by: Hannes Reinecke <[email protected]>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
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