RE: [PATCH v2 2/2] nvme/tcp: Add wq_unbound modparam for nvme_tcp_wq
From: Anton Gavriliuk
Date: Wed Mar 13 2024 - 17:12:47 EST
Thanks, it works.
Will it be added by default to the 6.9 mainline ?
Anton
-----Original Message-----
From: Li Feng <fengli@xxxxxxxxxx>
Sent: Wednesday, March 13, 2024 2:38 PM
To: Keith Busch <kbusch@xxxxxxxxxx>; Jens Axboe <axboe@xxxxxxxxx>; Christoph Hellwig <hch@xxxxxx>; Sagi Grimberg <sagi@xxxxxxxxxxx>; open list:NVM EXPRESS DRIVER <linux-nvme@xxxxxxxxxxxxxxxxxxx>; open list <linux-kernel@xxxxxxxxxxxxxxx>
Cc: Anton Gavriliuk <Anton.Gavriliuk@xxxxxx>; Li Feng <fengli@xxxxxxxxxx>
Subject: [PATCH v2 2/2] nvme/tcp: Add wq_unbound modparam for nvme_tcp_wq
The default nvme_tcp_wq will use all CPUs to process tasks. Sometimes it is necessary to set CPU affinity to improve performance.
A new module parameter wq_unbound is added here. If set to true, users can configure cpu affinity through /sys/devices/virtual/workqueue/nvme_tcp_wq/cpumask.
Signed-off-by: Li Feng <fengli@xxxxxxxxxx>
---
drivers/nvme/host/tcp.c | 21 ++++++++++++++++++---
1 file changed, 18 insertions(+), 3 deletions(-)
diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c index 2ec1186db0a3..34a882b2ec53 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -36,6 +36,14 @@ static int so_priority; module_param(so_priority, int, 0644); MODULE_PARM_DESC(so_priority, "nvme tcp socket optimize priority");
+/*
+ * Use the unbound workqueue for nvme_tcp_wq, then we can set the cpu
+affinity
+ * from sysfs.
+ */
+static bool wq_unbound;
+module_param(wq_unbound, bool, 0644);
+MODULE_PARM_DESC(wq_unbound, "Use unbound workqueue for nvme-tcp IO
+context (default false)");
+
/*
* TLS handshake timeout
*/
@@ -1551,7 +1559,10 @@ static void nvme_tcp_set_queue_io_cpu(struct nvme_tcp_queue *queue)
else if (nvme_tcp_poll_queue(queue))
n = qid - ctrl->io_queues[HCTX_TYPE_DEFAULT] -
ctrl->io_queues[HCTX_TYPE_READ] - 1;
- queue->io_cpu = cpumask_next_wrap(n - 1, cpu_online_mask, -1, false);
+ if (wq_unbound)
+ queue->io_cpu = WORK_CPU_UNBOUND;
+ else
+ queue->io_cpu = cpumask_next_wrap(n - 1, cpu_online_mask, -1, false);
}
static void nvme_tcp_tls_done(void *data, int status, key_serial_t pskid) @@ -2790,6 +2801,8 @@ static struct nvmf_transport_ops nvme_tcp_transport = {
static int __init nvme_tcp_init_module(void) {
+ unsigned int wq_flags = WQ_MEM_RECLAIM | WQ_HIGHPRI | WQ_SYSFS;
+
BUILD_BUG_ON(sizeof(struct nvme_tcp_hdr) != 8);
BUILD_BUG_ON(sizeof(struct nvme_tcp_cmd_pdu) != 72);
BUILD_BUG_ON(sizeof(struct nvme_tcp_data_pdu) != 24); @@ -2799,8 +2812,10 @@ static int __init nvme_tcp_init_module(void)
BUILD_BUG_ON(sizeof(struct nvme_tcp_icresp_pdu) != 128);
BUILD_BUG_ON(sizeof(struct nvme_tcp_term_pdu) != 24);
- nvme_tcp_wq = alloc_workqueue("nvme_tcp_wq",
- WQ_MEM_RECLAIM | WQ_HIGHPRI | WQ_SYSFS, 0);
+ if (wq_unbound)
+ wq_flags |= WQ_UNBOUND;
+
+ nvme_tcp_wq = alloc_workqueue("nvme_tcp_wq", wq_flags, 0);
if (!nvme_tcp_wq)
return -ENOMEM;
--
2.44.0
Anton
-----Original Message-----
From: Li Feng <fengli@xxxxxxxxxx>
Sent: Wednesday, March 13, 2024 2:38 PM
To: Keith Busch <kbusch@xxxxxxxxxx>; Jens Axboe <axboe@xxxxxxxxx>; Christoph Hellwig <hch@xxxxxx>; Sagi Grimberg <sagi@xxxxxxxxxxx>; open list:NVM EXPRESS DRIVER <linux-nvme@xxxxxxxxxxxxxxxxxxx>; open list <linux-kernel@xxxxxxxxxxxxxxx>
Cc: Anton Gavriliuk <Anton.Gavriliuk@xxxxxx>; Li Feng <fengli@xxxxxxxxxx>
Subject: [PATCH v2 2/2] nvme/tcp: Add wq_unbound modparam for nvme_tcp_wq
The default nvme_tcp_wq will use all CPUs to process tasks. Sometimes it is necessary to set CPU affinity to improve performance.
A new module parameter wq_unbound is added here. If set to true, users can configure cpu affinity through /sys/devices/virtual/workqueue/nvme_tcp_wq/cpumask.
Signed-off-by: Li Feng <fengli@xxxxxxxxxx>
---
drivers/nvme/host/tcp.c | 21 ++++++++++++++++++---
1 file changed, 18 insertions(+), 3 deletions(-)
diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c index 2ec1186db0a3..34a882b2ec53 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -36,6 +36,14 @@ static int so_priority; module_param(so_priority, int, 0644); MODULE_PARM_DESC(so_priority, "nvme tcp socket optimize priority");
+/*
+ * Use the unbound workqueue for nvme_tcp_wq, then we can set the cpu
+affinity
+ * from sysfs.
+ */
+static bool wq_unbound;
+module_param(wq_unbound, bool, 0644);
+MODULE_PARM_DESC(wq_unbound, "Use unbound workqueue for nvme-tcp IO
+context (default false)");
+
/*
* TLS handshake timeout
*/
@@ -1551,7 +1559,10 @@ static void nvme_tcp_set_queue_io_cpu(struct nvme_tcp_queue *queue)
else if (nvme_tcp_poll_queue(queue))
n = qid - ctrl->io_queues[HCTX_TYPE_DEFAULT] -
ctrl->io_queues[HCTX_TYPE_READ] - 1;
- queue->io_cpu = cpumask_next_wrap(n - 1, cpu_online_mask, -1, false);
+ if (wq_unbound)
+ queue->io_cpu = WORK_CPU_UNBOUND;
+ else
+ queue->io_cpu = cpumask_next_wrap(n - 1, cpu_online_mask, -1, false);
}
static void nvme_tcp_tls_done(void *data, int status, key_serial_t pskid) @@ -2790,6 +2801,8 @@ static struct nvmf_transport_ops nvme_tcp_transport = {
static int __init nvme_tcp_init_module(void) {
+ unsigned int wq_flags = WQ_MEM_RECLAIM | WQ_HIGHPRI | WQ_SYSFS;
+
BUILD_BUG_ON(sizeof(struct nvme_tcp_hdr) != 8);
BUILD_BUG_ON(sizeof(struct nvme_tcp_cmd_pdu) != 72);
BUILD_BUG_ON(sizeof(struct nvme_tcp_data_pdu) != 24); @@ -2799,8 +2812,10 @@ static int __init nvme_tcp_init_module(void)
BUILD_BUG_ON(sizeof(struct nvme_tcp_icresp_pdu) != 128);
BUILD_BUG_ON(sizeof(struct nvme_tcp_term_pdu) != 24);
- nvme_tcp_wq = alloc_workqueue("nvme_tcp_wq",
- WQ_MEM_RECLAIM | WQ_HIGHPRI | WQ_SYSFS, 0);
+ if (wq_unbound)
+ wq_flags |= WQ_UNBOUND;
+
+ nvme_tcp_wq = alloc_workqueue("nvme_tcp_wq", wq_flags, 0);
if (!nvme_tcp_wq)
return -ENOMEM;
--
2.44.0