| Message ID | 1462204442-3368-1-git-send-email-jonathan.derrick@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, May 02, 2016 at 09:54:02AM -0600, Jon Derrick wrote: > This patch changes the use_cmb_sqes module parameter to read-only. This > parameter allows the driver to place IO submission queues within the > Controller Memory Buffer. The parameter is currently writable through > sysfs at /sys/module/nvme/parameters/use_cmb_sqes. > > Memory allocations for queues aren't dynamically reallocated between > resets. For this reason, allowing the use_cmb_sqes module parameter to > be written while the drive is loaded may be confusing because we have no > mechanism to dynamically remap the queues. I agree, so: Reviewed-by: Christoph Hellwig <hch@lst.de> But re-reviewing this again I really hate the whole idea of the user having to chose what to do with the CMB. Can you just add a quirk to do the right thing for the controller(s) you care about, and work with the NVMe TWG to have a standardized way for the controllers to give this information to the host? -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index 4fd733f..83de5569 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -61,7 +61,7 @@ static int use_threaded_interrupts; module_param(use_threaded_interrupts, int, 0); static bool use_cmb_sqes = true; -module_param(use_cmb_sqes, bool, 0644); +module_param(use_cmb_sqes, bool, 0444); MODULE_PARM_DESC(use_cmb_sqes, "use controller's memory buffer for I/O SQes"); static struct workqueue_struct *nvme_workq;
This patch changes the use_cmb_sqes module parameter to read-only. This parameter allows the driver to place IO submission queues within the Controller Memory Buffer. The parameter is currently writable through sysfs at /sys/module/nvme/parameters/use_cmb_sqes. Memory allocations for queues aren't dynamically reallocated between resets. For this reason, allowing the use_cmb_sqes module parameter to be written while the drive is loaded may be confusing because we have no mechanism to dynamically remap the queues. Signed-off-by: Jon Derrick <jonathan.derrick@intel.com> --- v2: More thorough log message drivers/nvme/host/pci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)