On 2023/7/13 12:52, Paul E. McKenney wrote:
On Thu, Jul 13, 2023 at 12:41:09PM +0800, Gao Xiang wrote:
...
There are lots of performance issues here and even a plumber
topic last year to show that, see:
[1] https://lore.kernel.org/r/20230519001709.2563-1-tj@xxxxxxxxxx
[2] https://lore.kernel.org/r/CAHk-=wgE9kORADrDJ4nEsHHLirqPCZ1tGaEPAZejHdZ03qCOGg@xxxxxxxxxxxxxx
[3] https://lore.kernel.org/r/CAB=BE-SBtO6vcoyLNA9F-9VaN5R0t3o_Zn+FW8GbO6wyUqFneQ@xxxxxxxxxxxxxx
[4] https://lpc.events/event/16/contributions/1338/
and more.
I'm not sure if it's necessary to look info all of that,
andSandeep knows more than I am (the scheduling issue
becomes vital on some aarch64 platform.)
Hmmm... Please let me try again.
Assuming that this approach turns out to make sense, the resulting
patch will need to clearly state the performance benefits directly in
the commit log.
And of course, for the approach to make sense, it must avoid breaking
the existing lockdep-RCU debugging code.
Is that more clear?
Personally I'm not working on Android platform any more so I don't
have a way to reproduce, hopefully Sandeep could give actually
number _again_ if dm-verity is enabled and trigger another
workqueue here and make a comparsion why the scheduling latency of
the extra work becomes unacceptable.
Thanks,
Gao Xiang
