* [PATCH 1/3] nvme: Add warning for PST table memory allocation failure in nvme_configure_apst
2025-03-26 9:57 [PATCH 0/3] nvme: Add sysfs interface for APST configuration management Yaxiong Tian
@ 2025-03-26 10:15 ` Yaxiong Tian
2025-03-26 10:16 ` [PATCH 2/3] nvme: add sysfs interface for APST table updates Yaxiong Tian
2025-03-26 10:16 ` [PATCH 3/3] nvme: add per-controller sysfs interface for APST configuration Yaxiong Tian
2 siblings, 0 replies; 6+ messages in thread
From: Yaxiong Tian @ 2025-03-26 10:15 UTC (permalink / raw)
To: kbusch, axboe, hch, sagi; +Cc: linux-nvme, linux-kernel, Yaxiong Tian
From: Yaxiong Tian <tianyaxiong@kylinos.cn>
Currently the function fails silently on PST table memory allocation failure.
Add warning messages to improve error visibility.
Signed-off-by: Yaxiong Tian <tianyaxiong@kylinos.cn>
---
drivers/nvme/host/core.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index c2d89fac86c5..fb0404fee551 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2678,8 +2678,10 @@ static int nvme_configure_apst(struct nvme_ctrl *ctrl)
}
table = kzalloc(sizeof(*table), GFP_KERNEL);
- if (!table)
+ if (!table) {
+ dev_warn(ctrl->device, "Failed to allocate pst table; not using APST\n");
return 0;
+ }
if (!ctrl->apst_enabled || ctrl->ps_max_latency_us == 0) {
/* Turn off APST. */
--
2.25.1
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH 2/3] nvme: add sysfs interface for APST table updates
2025-03-26 9:57 [PATCH 0/3] nvme: Add sysfs interface for APST configuration management Yaxiong Tian
2025-03-26 10:15 ` [PATCH 1/3] nvme: Add warning for PST table memory allocation failure in nvme_configure_apst Yaxiong Tian
@ 2025-03-26 10:16 ` Yaxiong Tian
2025-03-26 10:16 ` [PATCH 3/3] nvme: add per-controller sysfs interface for APST configuration Yaxiong Tian
2 siblings, 0 replies; 6+ messages in thread
From: Yaxiong Tian @ 2025-03-26 10:16 UTC (permalink / raw)
To: kbusch, axboe, hch, sagi; +Cc: linux-nvme, linux-kernel, Yaxiong Tian
From: Yaxiong Tian <tianyaxiong@kylinos.cn>
Currently, the APST (Autonomous Power State Transition) table can only be
updated during module initialization via module parameters or indirectly
by setting QoS latency requirements. This patch adds a direct sysfs
interface to allow dynamic updates to the APST table at runtime.
The new sysfs entry is created at:
/sys/class/nvme/<controller>/apst_update
This provides more flexibility in power management tuning without
requiring module reload or QoS latency changes.
Example usage:
update nvme module parameters.
echo 1 > /sys/class/nvme/nvme0/apst_update
Signed-off-by: Yaxiong Tian <tianyaxiong@kylinos.cn>
---
drivers/nvme/host/core.c | 4 +++-
drivers/nvme/host/nvme.h | 2 ++
drivers/nvme/host/sysfs.c | 23 +++++++++++++++++++++++
3 files changed, 28 insertions(+), 1 deletion(-)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index fb0404fee551..cfce433c5553 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2654,7 +2654,7 @@ static bool nvme_apst_get_transition_time(u64 total_latency,
*
* Users can set ps_max_latency_us to zero to turn off APST.
*/
-static int nvme_configure_apst(struct nvme_ctrl *ctrl)
+int nvme_configure_apst(struct nvme_ctrl *ctrl)
{
struct nvme_feat_auto_pst *table;
unsigned apste = 0;
@@ -4852,6 +4852,8 @@ int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev,
ctrl->ka_cmd.common.opcode = nvme_admin_keep_alive;
ctrl->ka_last_check_time = jiffies;
+ mutex_init(&ctrl->apst_lock);
+
BUILD_BUG_ON(NVME_DSM_MAX_RANGES * sizeof(struct nvme_dsm_range) >
PAGE_SIZE);
ctrl->discard_page = alloc_page(GFP_KERNEL);
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 51e078642127..7f8e10f5bf7a 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -385,6 +385,7 @@ struct nvme_ctrl {
key_serial_t tls_pskid;
/* Power saving configuration */
+ struct mutex apst_lock;
u64 ps_max_latency_us;
bool apst_enabled;
@@ -828,6 +829,7 @@ void nvme_unfreeze(struct nvme_ctrl *ctrl);
void nvme_wait_freeze(struct nvme_ctrl *ctrl);
int nvme_wait_freeze_timeout(struct nvme_ctrl *ctrl, long timeout);
void nvme_start_freeze(struct nvme_ctrl *ctrl);
+int nvme_configure_apst(struct nvme_ctrl *ctrl);
static inline enum req_op nvme_req_op(struct nvme_command *cmd)
{
diff --git a/drivers/nvme/host/sysfs.c b/drivers/nvme/host/sysfs.c
index 6d31226f7a4f..5003cb294d65 100644
--- a/drivers/nvme/host/sysfs.c
+++ b/drivers/nvme/host/sysfs.c
@@ -684,6 +684,28 @@ static DEVICE_ATTR(dhchap_ctrl_secret, S_IRUGO | S_IWUSR,
nvme_ctrl_dhchap_ctrl_secret_show, nvme_ctrl_dhchap_ctrl_secret_store);
#endif
+static ssize_t apst_update_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ int err;
+ bool bool_data = false;
+ struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+ err = kstrtobool(buf, &bool_data);
+
+ if (err)
+ return err;
+
+ if (bool_data && nvme_ctrl_state(ctrl) == NVME_CTRL_LIVE) {
+ mutex_lock(&ctrl->apst_lock);
+ nvme_configure_apst(ctrl);
+ mutex_unlock(&ctrl->apst_lock);
+ }
+
+ return size;
+}
+static DEVICE_ATTR_WO(apst_update);
+
static struct attribute *nvme_dev_attrs[] = {
&dev_attr_reset_controller.attr,
&dev_attr_rescan_controller.attr,
@@ -712,6 +734,7 @@ static struct attribute *nvme_dev_attrs[] = {
&dev_attr_dhchap_ctrl_secret.attr,
#endif
&dev_attr_adm_passthru_err_log_enabled.attr,
+ &dev_attr_apst_update.attr,
NULL
};
--
2.25.1
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH 3/3] nvme: add per-controller sysfs interface for APST configuration
2025-03-26 9:57 [PATCH 0/3] nvme: Add sysfs interface for APST configuration management Yaxiong Tian
2025-03-26 10:15 ` [PATCH 1/3] nvme: Add warning for PST table memory allocation failure in nvme_configure_apst Yaxiong Tian
2025-03-26 10:16 ` [PATCH 2/3] nvme: add sysfs interface for APST table updates Yaxiong Tian
@ 2025-03-26 10:16 ` Yaxiong Tian
2 siblings, 0 replies; 6+ messages in thread
From: Yaxiong Tian @ 2025-03-26 10:16 UTC (permalink / raw)
To: kbusch, axboe, hch, sagi; +Cc: linux-nvme, linux-kernel, Yaxiong Tian
From: Yaxiong Tian <tianyaxiong@kylinos.cn>
Currently, APST (Autonomous Power State Transition) parameters are
configured as module parameters affecting all controllers uniformly,
This lacks flexibility for heterogeneous systems.
This patch introduces per-controller sysfs attributes under each NVMe
controller's sysfs directory:
- apst_primary_timeout_ms
- apst_secondary_timeout_ms
- apst_primary_latency_tol_us
- apst_secondary_latency_tol_us
The attributes allow runtime configuration of:
1. Timeout values for primary/secondary states
2. Latency tolerance requirements
The existing module parameters are retained for backward compatibility
but now only serve as default values for new controllers.
Signed-off-by: Yaxiong Tian <tianyaxiong@kylinos.cn>
---
drivers/nvme/host/core.c | 16 ++++++++++------
drivers/nvme/host/nvme.h | 4 ++++
drivers/nvme/host/sysfs.c | 36 ++++++++++++++++++++++++++++++++++++
3 files changed, 50 insertions(+), 6 deletions(-)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index cfce433c5553..812e0a1f3b53 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2608,22 +2608,22 @@ static int nvme_configure_host_options(struct nvme_ctrl *ctrl)
* timeout value is returned and the matching tolerance index (1 or 2) is
* reported.
*/
-static bool nvme_apst_get_transition_time(u64 total_latency,
+static bool nvme_apst_get_transition_time(struct nvme_ctrl *ctrl, u64 total_latency,
u64 *transition_time, unsigned *last_index)
{
- if (total_latency <= apst_primary_latency_tol_us) {
+ if (total_latency <= ctrl->apst_primary_latency_tol_us) {
if (*last_index == 1)
return false;
*last_index = 1;
- *transition_time = apst_primary_timeout_ms;
+ *transition_time = ctrl->apst_primary_timeout_ms;
return true;
}
if (apst_secondary_timeout_ms &&
- total_latency <= apst_secondary_latency_tol_us) {
+ total_latency <= ctrl->apst_secondary_latency_tol_us) {
if (*last_index <= 2)
return false;
*last_index = 2;
- *transition_time = apst_secondary_timeout_ms;
+ *transition_time = ctrl->apst_secondary_timeout_ms;
return true;
}
return false;
@@ -2728,7 +2728,7 @@ int nvme_configure_apst(struct nvme_ctrl *ctrl)
* for higher power states.
*/
if (apst_primary_timeout_ms && apst_primary_latency_tol_us) {
- if (!nvme_apst_get_transition_time(total_latency_us,
+ if (!nvme_apst_get_transition_time(ctrl, total_latency_us,
&transition_ms, &last_lt_index))
continue;
} else {
@@ -4853,6 +4853,10 @@ int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev,
ctrl->ka_last_check_time = jiffies;
mutex_init(&ctrl->apst_lock);
+ ctrl->apst_primary_timeout_ms = apst_primary_timeout_ms;
+ ctrl->apst_secondary_timeout_ms = apst_secondary_timeout_ms;
+ ctrl->apst_primary_latency_tol_us = apst_primary_latency_tol_us;
+ ctrl->apst_secondary_latency_tol_us = apst_secondary_latency_tol_us;
BUILD_BUG_ON(NVME_DSM_MAX_RANGES * sizeof(struct nvme_dsm_range) >
PAGE_SIZE);
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 7f8e10f5bf7a..ed9afc3c6781 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -387,6 +387,10 @@ struct nvme_ctrl {
/* Power saving configuration */
struct mutex apst_lock;
u64 ps_max_latency_us;
+ u64 apst_primary_timeout_ms;
+ u64 apst_secondary_timeout_ms;
+ u64 apst_primary_latency_tol_us;
+ u64 apst_secondary_latency_tol_us;
bool apst_enabled;
/* PCIe only: */
diff --git a/drivers/nvme/host/sysfs.c b/drivers/nvme/host/sysfs.c
index 5003cb294d65..afa61e9c1366 100644
--- a/drivers/nvme/host/sysfs.c
+++ b/drivers/nvme/host/sysfs.c
@@ -684,6 +684,37 @@ static DEVICE_ATTR(dhchap_ctrl_secret, S_IRUGO | S_IWUSR,
nvme_ctrl_dhchap_ctrl_secret_show, nvme_ctrl_dhchap_ctrl_secret_store);
#endif
+#define nvme_apst_show_and_store_function(field) \
+static ssize_t field##_show(struct device *dev, \
+ struct device_attribute *attr, char *buf) \
+{ \
+ struct nvme_ctrl *ctrl = dev_get_drvdata(dev); \
+ return sysfs_emit(buf, "%llu\n", ctrl->field); \
+} \
+ \
+static ssize_t field##_store(struct device *dev, \
+ struct device_attribute *attr, \
+ const char *buf, size_t size) \
+{ \
+ int err; \
+ u64 data = 0; \
+ struct nvme_ctrl *ctrl = dev_get_drvdata(dev); \
+ err = kstrtou64(buf, 0, &data); \
+ if (err < 0) \
+ return err; \
+ \
+ mutex_lock(&ctrl->apst_lock); \
+ ctrl->field = data; \
+ mutex_unlock(&ctrl->apst_lock); \
+ return size; \
+} \
+static DEVICE_ATTR_RW(field);
+
+nvme_apst_show_and_store_function(apst_primary_timeout_ms);
+nvme_apst_show_and_store_function(apst_secondary_timeout_ms);
+nvme_apst_show_and_store_function(apst_primary_latency_tol_us);
+nvme_apst_show_and_store_function(apst_secondary_latency_tol_us);
+
static ssize_t apst_update_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t size)
@@ -734,6 +765,11 @@ static struct attribute *nvme_dev_attrs[] = {
&dev_attr_dhchap_ctrl_secret.attr,
#endif
&dev_attr_adm_passthru_err_log_enabled.attr,
+
+ &dev_attr_apst_primary_timeout_ms.attr,
+ &dev_attr_apst_secondary_timeout_ms.attr,
+ &dev_attr_apst_primary_latency_tol_us.attr,
+ &dev_attr_apst_secondary_latency_tol_us.attr,
&dev_attr_apst_update.attr,
NULL
};
--
2.25.1
^ permalink raw reply [flat|nested] 6+ messages in thread