On Mon, 17 Aug 2009, Rafael J. Wysocki wrote: > On Wednesday 12 August 2009, Rafael J. Wysocki wrote: > > Hi, > > > > The following patches introduce a mechanism allowing us to execute device > > drivers' suspend and resume callbacks asynchronously during system sleep > > transitions, such as suspend to RAM. The idea is explained in the [1/1] patch > > message. > > Changes: > > * Added [1/7] that fixes kerneldoc comments in drivers/base/power/main.c > (this is a 2.6.32 candidate). > > * Added [2/7] adding a framework for representing PM link (idea described > in the patch message). > > * [3/7] is the async resume patch (idea described in the patch message). > > * [4/7] is the async suspend patch. > > * [5/7] - [7/7] set async_suspend for devices in a few selected subsystems. > > The patches have been tested on HP nx6325. > > Comments welcome. I'm not sure about the design of these things. How much do we care about wasting memory? Your scheme allocates six pointers for every dependency, plus four pointers for every device. It's possible to reduce this considerably, especially if the parent-child dependencies aren't stored explicitly. If you decide to keep this scheme, you should make pm_link_add() check for duplicate dependencies before adding them. Also, I think a better approach to the async execution would not require adding a struct completion to each device and making each async thread wait for the completion to be signalled. Instead, have a single master thread (i.e., the thread doing the suspend) monitor the dependencies and have it farm the devices out to async threads as they become ready to be suspended or resumed. Finally, devices that don't have async_suspend set should implicitly depend on everything that comes after them (for suspend) or before them (for resume) in the device list. Alan Stern -- 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
