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| author | Hannes Reinecke <hare@suse.de> | 2021-12-20 13:51:45 +0100 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2021-12-23 11:22:46 +0100 |
| commit | e3d347943919f35ccdeed8d2cc62e8c6c12b36cd (patch) | |
| tree | 361f6bebf41cb28c5f4a846d2cc294683db5f91a /drivers/nvme/host/multipath.c | |
| parent | nvme: drop unused variable ctrl in nvme_setup_cmd (diff) | |
| download | linux-e3d347943919f35ccdeed8d2cc62e8c6c12b36cd.tar.xz linux-e3d347943919f35ccdeed8d2cc62e8c6c12b36cd.zip | |
nvme: add 'iopolicy' module parameter
While the 'iopolicy' sysfs attribute can be set at runtime, most
storage arrays prefer to use the 'round-robin' iopolicy per default.
We can use udev rules to set this, but is getting rather unwieldy
for rebranded arrays as we would have to update the udev rules
anytime a new array shows up, leading to the same mess we currently
have in multipathd for configuring the RDAC arrays.
Hence this patch adds a module parameter 'iopolicy' to allow the
admin to switch the default, and to do away with the need for a
udev rule here.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'drivers/nvme/host/multipath.c')
| -rw-r--r-- | drivers/nvme/host/multipath.c | 41 |
1 files changed, 36 insertions, 5 deletions
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c index 7f2071f2460c..892bd5dcb46b 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -13,6 +13,42 @@ module_param(multipath, bool, 0444); MODULE_PARM_DESC(multipath, "turn on native support for multiple controllers per subsystem"); +static const char *nvme_iopolicy_names[] = { + [NVME_IOPOLICY_NUMA] = "numa", + [NVME_IOPOLICY_RR] = "round-robin", +}; + +static int iopolicy = NVME_IOPOLICY_NUMA; + +static int nvme_set_iopolicy(const char *val, const struct kernel_param *kp) +{ + if (!val) + return -EINVAL; + if (!strncmp(val, "numa", 4)) + iopolicy = NVME_IOPOLICY_NUMA; + else if (!strncmp(val, "round-robin", 11)) + iopolicy = NVME_IOPOLICY_RR; + else + return -EINVAL; + + return 0; +} + +static int nvme_get_iopolicy(char *buf, const struct kernel_param *kp) +{ + return sprintf(buf, "%s\n", nvme_iopolicy_names[iopolicy]); +} + +module_param_call(iopolicy, nvme_set_iopolicy, nvme_get_iopolicy, + &iopolicy, 0644); +MODULE_PARM_DESC(iopolicy, + "Default multipath I/O policy; 'numa' (default) or 'round-robin'"); + +void nvme_mpath_default_iopolicy(struct nvme_subsystem *subsys) +{ + subsys->iopolicy = iopolicy; +} + void nvme_mpath_unfreeze(struct nvme_subsystem *subsys) { struct nvme_ns_head *h; @@ -706,11 +742,6 @@ void nvme_mpath_stop(struct nvme_ctrl *ctrl) struct device_attribute subsys_attr_##_name = \ __ATTR(_name, _mode, _show, _store) -static const char *nvme_iopolicy_names[] = { - [NVME_IOPOLICY_NUMA] = "numa", - [NVME_IOPOLICY_RR] = "round-robin", -}; - static ssize_t nvme_subsys_iopolicy_show(struct device *dev, struct device_attribute *attr, char *buf) { |