[PATCH v3 1/4] scsi: scan: allocate sdev and starget on the NUMA node of the host adapter
From: Sumit Saxena <sumit.saxena@broadcom.com>
Date: 2026-06-09 11:49:02
Also in:
linux-block, linux-hyperv, linux-scsi, target-devel, virtualization, xen-devel
Subsystem:
scsi subsystem, the rest · Maintainers:
"James E.J. Bottomley", "Martin K. Petersen", Linus Torvalds
From: James Rizzo <redacted> 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 <redacted> Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com> --- drivers/scsi/scsi_scan.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index e27da038603a..121a14d5fdb8 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c@@ -34,6 +34,7 @@ #include <linux/kthread.h> #include <linux/spinlock.h> #include <linux/async.h> +#include <linux/topology.h> #include <linux/slab.h> #include <linux/unaligned.h>
@@ -287,8 +288,8 @@ static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget, struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); struct queue_limits lim; - sdev = kzalloc(sizeof(*sdev) + shost->transportt->device_size, - GFP_KERNEL); + sdev = kzalloc_node(sizeof(*sdev) + shost->transportt->device_size, + GFP_KERNEL, dev_to_node(shost->dma_dev)); if (!sdev) goto out;
@@ -502,7 +503,7 @@ static struct scsi_target *scsi_alloc_target(struct device *parent, struct scsi_target *found_target; int error, ref_got; - starget = kzalloc(size, GFP_KERNEL); + starget = kzalloc_node(size, GFP_KERNEL, dev_to_node(shost->dma_dev)); if (!starget) { printk(KERN_ERR "%s: allocation failure\n", __func__); return NULL;
--
2.43.7