From bf2d650391be508dd8b5e188b65ed32300cf3489 Mon Sep 17 00:00:00 2001 From: Mike Christie Date: Tue, 3 Dec 2024 13:15:09 -0600 Subject: [PATCH] vhost-scsi: Allocate T10 PI structs only when enabled T10 PI is not a widely used feature. This has us only allocate the structs for it if the feature has been enabled. For a common small setup where you have 1 virtqueue and 128 commands per queue, this saves: 8MB = 32 bytes per sg * 2048 entries * 128 commands per vhost-scsi device. Signed-off-by: Mike Christie Message-Id: <20241203191705.19431-3-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin Acked-by: Stefan Hajnoczi --- drivers/vhost/scsi.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index c266171045c5..e361c43d0730 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -1651,12 +1651,14 @@ static int vhost_scsi_setup_vq_cmds(struct vhost_virtqueue *vq, int max_cmds) goto out; } - tv_cmd->tvc_prot_sgl = kcalloc(VHOST_SCSI_PREALLOC_PROT_SGLS, - sizeof(struct scatterlist), - GFP_KERNEL); - if (!tv_cmd->tvc_prot_sgl) { - pr_err("Unable to allocate tv_cmd->tvc_prot_sgl\n"); - goto out; + if (vhost_has_feature(vq, VIRTIO_SCSI_F_T10_PI)) { + tv_cmd->tvc_prot_sgl = kcalloc(VHOST_SCSI_PREALLOC_PROT_SGLS, + sizeof(struct scatterlist), + GFP_KERNEL); + if (!tv_cmd->tvc_prot_sgl) { + pr_err("Unable to allocate tv_cmd->tvc_prot_sgl\n"); + goto out; + } } } return 0;