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On Thu, 2003-04-24 at 12:45, Martin J. Bligh wrote: > > I don't believer I've ever seen things get OOM killed. Instead, page > > cache is discarded until things do fit. > > What happens if user allocated pages are filling up all the space, > not page cache? Trust me, it happens ;-) Yep, just because I haven't seen it, doesn't mean a thing. :>. In that case, there are two issues: memory to work in to start with and how to save the image without corrupting it. Regarding #1, there must still be some memory available, mustn't there? swsusp only approx (nrpages in use/256) pages to do its work. Surely we'd always be able to get .4% of the number of pages? Even if we can't get that many, we should be able to adjust the algorithm to be able to suspend a machine with only 10 or so pages available to start with (no, I'm not volunteering to do it! I want to merge with 2.5 and get on to other projects!). 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. 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 :> Regards, Nigel -- Nigel Cunningham 495 St Georges Road South, Hastings 4201, New Zealand Be diligent to present yourself approved to God as a workman who does not need to be ashamed, handling accurately the word of truth. -- 2 Timothy 2:14, NASB. - 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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