On 8/3/21 11:07 PM, Greg KH wrote:
Should we just bump it up anyway given that modern memory limits are probably more now?
As mentioned in the patch description, this patch is not about saving memory but about reducing latency. Reducing the queue depth to control latency is a common approach for block storage. See e.g. the description of CONFIG_BLK_WBT in block/Kconfig.
You may want to know that I looked into reducing the queue depth from user space before I came up with this kernel patch (https://android-review.googlesource.com/c/platform/system/core/+/1783847/6). However, making that approach work requires significant changes in the Android SELinux sysfs labeling policy. From my point of view, modifying the kernel is much less painful than reworking the Android SELinux labeling policy.
Bart.
