Hello, I've just hit a nasty bug in makedumpfile when page cache is filtered out (dump level bitmap includes 2 or 4). In short, makedumpfile checks PG_swapcache, but since commit 6326fec1122cde256bd2a8c63f2606e08e44ce1d this bit is an alias for PG_owner_priv_1. This bit is also used by filesystem code (PG_checked) and Xen (PG_pinned and PG_foreign). FTR I haven't hit an issue with the filsystem usage in practice, but all my Xen dumps are unusable, because PG_pinned is by design set for all page table pages. Anyway, it appears that PG_swapcache is valid only if PG_swapbacked is set. I have already submitted a patch to the Linux kernel to export the value of PG_swapbacked in VMCOREINFO: http://ozlabs.org/~akpm/mmotm/broken-out/kexec-export-pg_swapbacked-to-vmcoreinfo.patch I plan to make the corresponding makedumpfile change soon. However, it seems to me that PG_swapbacked alone should determine whether a page should be kept in the dump file, or filtered out. Why do we check PG_swapcache instead? PG_swapbacked first appeared in kernel 2.6.28, i.e. much later than makedumpfile. Is it simply that nobody has reviewed the logic since then? Petr T _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
