On Fri, 2013-06-07 at 18:16 -0700, Greg KH wrote: > On Sat, Jun 08, 2013 at 08:42:12AM +0800, Yanmin Zhang wrote: > > On Fri, 2013-06-07 at 12:36 +0200, Rafael J. Wysocki wrote: > > > On Friday, June 07, 2013 04:20:30 PM shuox....@intel.com wrote: > > > > dpm_run_callback is used in other stages of power states changing. > > > > It provides debug info message and time measurement when call these > > > > callback. We also want to benefit ->prepare and ->complete. > > > > > > > > [PATCH 1/2] PM: use dpm_run_callback in device_prepare > > > > [PATCH 2/2] PM: add dpm_run_callback_void and use it in device_complete > > > > > > Is this an "Oh, why don't we do that?" series, or is it useful for > > > anything > > > in practice? I'm asking, because we haven't added that stuff to start > > > with > > > since we didn't see why it would be useful to anyone. > > > > > > And while patch [1/2] reduces the code size (by 1 line), so I can see some > > > (tiny) benefit from applying it, patch [2/2] adds more code and is there > > > any > > > paractical reason? > > Sometimes, suspend-to-ram path spends too much time (either suspend slowly > > or wakeup slowly) and we need optimize it. > > With the 2 patches, we could collect initcall_debug printk info and manually > > check what prepare/complete callbacks consume too much time. > > But initcall information is for initialization stuff, not suspend/resume > things, right? initcall_debug also controls shutdown callbacks, and suspend/resume callbacks. See __device_suspend=>dpm_run_callback. It's very useful when we want to optimize suspend-to-ram, or debug some hard issues which happen when async suspend is enabled.
> Doesn't the existing tools for parsing this choke if it > sees the information at suspend/resume time? Current kernel doesn't print out info around prepare/complete. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
