Am 17.03.21 um 16:17 schrieb Alan Stern:
On Wed, Mar 17, 2021 at 01:21:50PM +0100, Hans de Goede wrote:
Hi,
On 3/16/21 6:04 PM, Alan Stern wrote:
I think it would be mildly better, but not a whole lot. Since the
Kindle describes itself as having removable media, the kernel normally
probes it periodically to make sure the media remains present. The
default probing interval is 2 seconds. Reducing it to 0.9 seconds
doesn't represent an exorbitant additional load IMO -- especially since
Kindles don't tend to spend huge amounts of time connected to computers.
Ah, I did not know that the default polling interval was that low(ish),
given that the default indeed is already that low, then changing it to
0.8 seconds would not be a big change. And we probably have a lot of
lower hanging fruit for unnecessary wakeups then that.
So we need to make a decision: Should the patch be merged, or should we
punt the issue to userspace tools?
On the plus side, the patch is rather small and non-invasive (although
it does allocate the last remaining bit in the 32-bit fflags field).
There's also the advantage of sending the extra command only when it is
needed, as opposed to increasing the overall frequency of TUR polling.
Any opinions?
I would vote to do in kernel as that is a cleaner solution:
1. It will work out of the box.
2. It only sends one extra command when needed.
3. It makes the block-device not break if user-space adjusts the poll
interval to higher values.
Matthias
