My initial idea was to execute only block device resume on the separate thread, as it take almost 80% of the total device resume time ( I did detailed profile of each device resume through rdtsc() counter) and rest of them takes less than 20% in total( each device ( including char and net)on its own takes less than 0.03 seconds). I could still save some good amount of resume time ( apprx 1.2 sec). However Given this ratio, and the fact that block device resume happening way at the end of the list, I tried this with only taking care of Block devices. I am not sure if there is a case where any scenario where Char devices would take more resume time than normally it would. If so I can modify the patch to put only block devices in separate thread for resume Thanks -hari -----Original Message----- From: Pavel Machek [mailto:pavel@xxxxxx] Sent: Friday, January 19, 2007 3:00 PM To: Seshadri, Harinarayanan Cc: inux-pm@xxxxxxxxxxxxxx; linux-acpi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx Subject: Re: [RFC] [PATCH] Power S3 Resume Optimization Patch. Request for Comment Hi! > [RFC][PATCH] Power S3 Resume optimisation > Here is a simple patch for optimising the S3 resume. With this > patch the resume time is 0.85. Given the fact that device initialisation > on the resume takes almost 70% of time, By executing the whole > "device_resume()" function on a seperate kernel thread, the resume gets > completed( ie. the user can precieve) by ~0.85 sec. Yep, but you also break it completely... > To avoid any possible race condition while processing the IO > request and to make sure all the io request are queued till the device > resume thread exits, the IO schedulars (patched cfq and as) checks a for > system_resume flag, which is set when the device resume thread starts, > if the flag is set, it doesnt put the request in the dispatch queue. > Once the flag is cleared i.e when the device resume thread is complete, > the IO-schedular behave as in normal situation. And you noticed that, so you fixed obvious problems on block devices. Ignoring char and net devices completely. > @@ -1088,6 +1088,19 @@ > if (list_empty(&ad->fifo_list[adir])) > return 0; > > + /* > + * Check here for the System resume flag to be cleared, if flag > is > + * still set the resume thread hasnt completed yet, and hence > dont > + * takeout any new request from the FIFO > + */ > + extern int system_resuming; > + if (system_resuming != 0) > + { Locking. CodingStyle. > -static void suspend_finish(suspend_state_t state) > +static int dev_resume_proc(void * data) > { > + /* Set the global resume flag, this will be checked by the > IO_schedular Broken mail client. > + * before dispatching the IO request > + */ > + system_resuming =1; Add mdelay(1 hour) here. Then try to use your wifi card and your tv grabber. > device_resume(); > + system_resuming = 0; > +#ifdef DEBUG > + printk(" reseting system_resume \n"); > +#endif Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html - To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
