> -----Original Message----- > From: kexec-bounces at lists.infradead.org > [mailto:kexec-bounces at lists.infradead.org] On Behalf Of Hatayama, Daisuke [..]> > > -----Original Message----- > > From: Atsushi Kumagai [mailto:kumagai-atsushi at mxc.nes.nec.co.jp] > > Sent: Tuesday, November 13, 2012 4:56 PM > [...] > > > - OFFSET(page._mapcount) > > > - OFFSET(page.private) > > > - SIZE(pageflags) > > > - NUMBER(PG_buddy) > > > - NUMBER(PG_slab) > > > - NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE) > > > > And I will post the patch to add the values above to the upstream kernel, > > so there is no problem on the future kernel. > > > > However, according to my tests, current makedumpfile can't get some of > the > > values above from VMLINUX and can't exclude free pages with the mem_map > > array logic. > > For example, page_is_buddy_v1() will be selected for kernel-3.4 with > > setup_page_is_buddy() due to not founding NUMBER(PG_buddy) and > > SIZE(pageflags), > > it's miss selection. > > > > Therefore, I propose to change the policy for excluding free page as below > > in order to take care of current kernels: > > > > 1. If VMCORE (or specified VMCOREINFO) includes the values above, > > using the mem_map array logic. > > > > 2. In other cases, using the current logic which uses free_list even > if > > running on cyclic mode. > > > > Of course, page_is_buddy_v1() and page_is_buddy_v2() should be retain > > because there is valuable for the user who can prepare VMCOREINFO. > > > > You are corrent. I'll repost the patch set soon. Rc1 or beta, which is better? > The patch I intend is like this, and this will be merged into the patch 06/10. $ git diff diff --git a/makedumpfile.c b/makedumpfile.c index 98eb640..f57612d 100644 --- a/makedumpfile.c +++ b/makedumpfile.c @@ -3730,8 +3730,8 @@ setup_page_is_buddy(void) else if (NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE) != NOT_FOUND_NUMBER) info->page_is_buddy = page_is_buddy_v3; else { - MSG("Can't select page_is_buddy handler; " - "filtering free pages is disabled.\n"); + DEBUG_MSG("Can't select page_is_buddy handler; " + "follow freelist instead of mem_map.\n"); } } else info->page_is_buddy = page_is_buddy_v2; @@ -4118,7 +4118,7 @@ exclude_unnecessary_pages_cyclic(void) if (info->dump_level & DL_EXCLUDE_CACHE || info->dump_level & DL_EXCLUDE_CACHE_PRI || info->dump_level & DL_EXCLUDE_USER_DATA || - info->dump_level & DL_EXCLUDE_FREE) { + ((info->dump_level & DL_EXCLUDE_FREE) && info->page_is_buddy)) { gettimeofday(&tv_start, NULL); @@ -4166,6 +4166,10 @@ update_cyclic_region(unsigned long long pfn) if (!exclude_unnecessary_pages_cyclic()) return FALSE; + if ((info->dump_level & DL_EXCLUDE_FREE) && !info->page_is_buddy) + if (!exclude_free_pages()) + return FALSE; + return TRUE; } @@ -5171,6 +5175,9 @@ get_loads_dumpfile_cyclic(void) return FALSE; if (!exclude_unnecessary_pages_cyclic()) return FALSE; + if ((info->dump_level & DL_EXCLUDE_FREE) && !info->page_is_buddy) + if (!exclude_free_pages()) + return FALSE; if (!(phnum = get_phnum_memory())) return FALSE; diff --git a/makedumpfile.h b/makedumpfile.h index 3ccc750..6ce8e23 100644 --- a/makedumpfile.h +++ b/makedumpfile.h @@ -1034,6 +1034,15 @@ struct DumpInfo { /* * for filtering free pages managed by buddy system: */ + /* + * Initialized by setup_page_is_buddy(). This can be NULL if + * + * 1) in non-cyclic mode, or + * 2) in cyclic mode, proper page_is_buddy handler fails to + * be detected. + * + * Then, conventional freelist logic is used instead. + */ int (*page_is_buddy)(unsigned long flags, unsigned int _mapcount, unsigned long private, unsigned int _count); }; Thanks. HATAYAMA, Daisuke
