Hi Matthieu, 2011/11/25 Matthieu CASTET <matthieu.castet@xxxxxxxxxx> > > Hi, > > but did embedded system will really use swap interface ? if you self-define the hibernation flow, you don't need swap. but for embedded system, we actually can still use the standard flow, swapon before hibernation, and swapoff after restore. so the swap partition only works as a partition to save used pages based on swap format. it is not a runtime swap partition at all. > > Often they don't have swap and can already save suspend image in disk/nand : > - SNAPSHOT_CREATE_IMAGE > - read it from /dev/snapshot and write it to a file. > > The only problem with the current interface, is that you can't SNAPSHOT_UNFREEZE > before reading the image. > But this is need for some filesystem that have thread. > > > For example we have a demo where we save the suspend image in a ubi volume and > restore it from bootloader. yes. we can definitely resume snapshot from bootloader directly, that depends on your self-defined hibernation flow. if that works well, it will save about 0.5s kernel boot time for a typical cortex-a9 ARM 1Ghz system. but you still need to take care you only compress and save used pages but not all pages. sync, drop page caches and kill non-system processes will help much to decrease hibernation image size. and standard hibernation flow will only save used pages, that is very important for decreasing snapshot size and restore faster. i am happy to hear you have a demo. do you have a website to show your demo and techinical details? > > > Matthieu > -barry _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/linux-pm
