> Yeah, we are wondering ourselves about that. Could you try cherry-picking > commit ad10eb079c97e27b4d27bc755c605226ce1625de (update migrate type on pcp > when isolating) from git://github.com/mina86/linux-2.6.git? It probably > won't > apply cleanly but resolving the conflicts should not be hard (alternatively > you can try branch cma from the same repo but it is a work in progress at > the > moment). > I'll try this patch and report back ,, >> is set to MIGRATE_CMA instead of MIGRATE_ISOLATED. > > > My understanding of that situation is that the page is on pcp list in which > cases it's page_private is not updated. Draining and the first patch in > the series (and also the commit I've pointed to above) are designed to fix > that but I'm unsure why they don't work all the time. > > Will verify this if the page is found on the pcp list as well . >> I've also had a test case where it failed because (page_count() != 0) With this, when it failed the page_count() returned a value of 2. I am not sure why, but I will try and see If I can reproduce this. > > >> Have you or anyone else seen this during the CMA testing? >> >> Also, could this be because we are finding a page within (start, end) >> that actually belongs to a higher order Buddy block ? > > > Higher order free buddy blocks are skipped in the “if (PageBuddy(page))” > path of __test_page_isolated_in_pageblock(). Then again, now that I think > of it, something fishy may be happening on the edges. Moving the check > outside of __alloc_contig_migrate_range() after outer_start is calculated > in alloc_contig_range() could help. I'll take a look at it. I was going to suggest that, moving the check until after outer_start is calculated will definitely help IMO. I am sure I've seen a case where page_count(page) = page->private = 0 and PageBuddy(page) was false. I will try and reproduce this as well. Thanks, Sandeep -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
