Messages in this thread | | | Date | Sun, 15 Apr 2012 14:46:19 +0200 | From | Per Olofsson <> | Subject | Re: [PATCH v10]: Hibernation: fix the number of pages used for hibernate/thaw buffering |
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2012-04-12 23:30, Bojan Smojver skrev: > I was thinking more like this: > ---------------------- > unsigned long read_pages = 0; > > [...] > > if (low_free_pages() > snapshot_get_image_size()) > read_pages = (low_free_pages() - snapshot_get_image_size()) / 2; > read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES); > ---------------------- > > Where LZO_MIN_RD_PAGES and LZO_MAX_RD_PAGES are set to 1024 and 8192, > respectively (this was picked empirically). > > Because we don't really know how many highmem pages are in the image > (this is figured out by prepare_image() function, half way through > reading the image - so way after this calculation is done), we assume > the worst case scenario. And that is that there are no highmem pages in > the image. > > Given that we cannot use pages from highmem for buffers anyway, the > above should be careful enough. Of course, there is still some > possibility of running out of pages, but the kernel is usually in a > pretty good shape memory-wise on image load, so we should be able to > squeeze a few MBs out of it, at least.
OK, I see your point now.
Yet another reason to switch to 64-bit then I guess :-)
-- Pelle
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