Messages in this thread | | | Date | Thu, 24 Apr 2003 11:27:42 +0200 | From | Pavel Machek <> | Subject | Re: Fix SWSUSP & !SWAP |
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Hi!
> > Regarding #2, my algorithm (ie not the version in 2.5 at the mo) > > separates pages to be saved into 2 types. Pageset1 are pages we expect > > to be needed during suspend. Pageset2 is those that will definitely not > > be needed. My algorithm for saving the data goes: Save pageset2 pages to > > disk then (as per the original/current method) make a copy of pageset1 > > pages (using the pageset2 locations + extra allocated memory if needsbe) > > and save the copy. Loading the image is the reverse process. Pageset 2 > > currently only consists of all highmem pages + active and inactive list > > pages. > > Not sure that quite works ... don't you need PTE's to know what to swap > out? Those can be in highmem. However, all user pages would fit in pageset > 2, I think. > > > If we refined the algorithm, perhaps that would address your > > issue. The other point here is that since we have to be able to make a > > copy of pageset1 pages, and since I haven't inlined kmap/unmap in the > > routine to copy pageset1 pages back on resume (Pavel will say whew to > > that, I'm sure!), pageset1 has a miximum size of half normal memory. I > > reckon refining the algoritm so that pageset1 can be [nearly] guaranteed > > to always be smaller is the better area to focus on, and I'm perfectly > > happy to try suggestions, particularly when they come in the form of a > > code fragment that include a call to SetPagePageset2(struct page * page) > > for the relevant targets :> > > The more I think about this, the more it seems so much simpler to just > require a reserved swap area the size of your RAM to suspend into. Would > make the code so much simpler ... forget the option bit I suggested earlier > ;-)
Reserved area does not make anything any simpler... Remember, you want to avoid having second set of poll-driven disk drivers just for suspend-to-disk. Its quite hard to design with that in mind. Pavel -- When do you have a heart between your knees? [Johanka's followup: and *two* hearts?] - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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