Hi Corinna, On Wed, 8 Sep 2021 12:04:21 +0200 Corinna Vinschen wrote: > On Sep 8 18:45, Takashi Yano wrote: > > On Wed, 8 Sep 2021 11:26:21 +0200 > > Corinna Vinschen wrote: > > > On Sep 8 11:01, Corinna Vinschen wrote: > > > > What exactly is the problem in the code which results in high CPU > > > > load? Can you explain this a bit? Maybe we need an entirely > > > > different approach to avoid that. > > > > > > I saw your new patch, but I don't see the problem. I typed a lot of > > > keys in mintty quickly and what happens is that the load of mintty > > > goes up to 9% on a 4 CPU system, but only temporarily while typing. > > > How do you reproduce the problem? > > > > Did you apply the patch > > 0001-Cygwin-select-Introduce-select_evt-event-for-pipe.patch > > or > > 0001-Cygwin-select-Introduce-select_sem-semaphore-for-pip.patch > > ? > > > > With these patch, the problem does not occur. The problem occurs > > with the commit dccde0dc. > > dccde0dc is 23bb19efcc45 in topic/pipe ATM (after force push) so, yes, > I'm running this with topic/pipe HEAD including this patch. > > > With my 4 core 8 thread CPU, CPU loads goes up to 12-13 % if > > I type keys using key repeat (30cps) after the commit dccde0dc. > > Oh, wow! As I wrote above, before applying "Cygwin: select: Introduce > select_sem semaphore for pipe." I only saw a 9% load. After applying > the patch I saw the same load. > > I don't know what I did differently, but after reverting your semaphore > patch I now see loads of up to 30%. So, never mind, apparently I tested > wrongly before. Your patch reduces the load tremendously. Thanks for testing again. > Just one question. Would you mind to split your patch into two parts, > one being just the revert of your "Improve select/poll response." patch > and one introducing select_sem? I split the patch as you advised. -- Takashi Yano