On 09/11/14 at 08:52am, Atsushi Kumagai wrote: > >Hi Atsushi, > > > >Since huge pages are included in user pages, I can't think of a way to > >make test cases for huge page exclusion. Could you give some suggestions > >on this or how did you test it? > > Before I posted this patch, I tested as below. > This idea came from the fact that old makedumpfile can't exclude > huge pages except the first page(PG_head). > > 1. Get the number of hugepages from /proc/meminfo > 2. Calculate the number of PG_tail pages > 3. Capture the dumpfile without filtering > 4. Run makedumpfile and compare the report message between v1.5.6 > and v1.5.7(rc) to get how many user pages become excludable with > this patch. > 5. The result of Step2's and Step4's must be same, confirm it. > > The way above is for THP but you can apply it also for hugetlbfs > if you take care of the things that old makedumpfile can't exclude > *any* hugetlbfs pages.
But THP is also Anonymous pages, doesn't it do the same for THP between 1.5.6 and 1.5.7? > > I recommend to separate the two cases completely by enabling either > THP or hugetlbfs explicitly since it's easier to confirm the results. For hugeTlbfs, this works, I will try this. > > > Thanks > Atsushi Kumagai > > > > >Thanks > >Baoquan > > > > > >On 08/20/14 at 07:27am, Atsushi Kumagai wrote: > >> There are 2 types of hugepages in the kernel, the both should be > >> excluded as user pages. > >> > >> 1. Transparent huge pages (THP) > >> All the pages are anonymous pages (at least for now), so we should > >> just get how many pages are in the corresponding hugepage. > >> It can be gotten from the page->lru.prev of the second page in the > >> hugepage. > >> > >> 2. Hugetlbfs pages > >> The pages aren't anonymous pages but kind of user pages, we should > >> exclude also these pages in any way. > >> Luckily, it's possible to detect these pages by looking the > >> page->lru.next of the second page in the hugepage. This idea came > >> from the kernel's PageHuge(). > >> The number of pages can be gotten in the same way as THP. > >> > >> Changelog: > >> v4: > >> - Cleaned up according to Petr's and Baoquan's comments. > >> v3: > >> - Cleaned up according to Petr's comments. > >> - Fix misdetection of hugetlb pages. > >> v2: > >> - Rebased to "Generic multi-page exclusion". > >> > >> Signed-off-by: Atsushi Kumagai <[email protected]> > >> --- > >> makedumpfile.c | 86 > >> ++++++++++++++++++++++++++++++++++++++++++++++++---------- > >> makedumpfile.h | 7 +++++ > >> 2 files changed, 78 insertions(+), 15 deletions(-) > >> > >> diff --git a/makedumpfile.c b/makedumpfile.c > >> index 11cd473..b4b6eca 100644 > >> --- a/makedumpfile.c > >> +++ b/makedumpfile.c > >> @@ -1180,6 +1180,7 @@ get_symbol_info(void) > >> SYMBOL_INIT(vmemmap_list, "vmemmap_list"); > >> SYMBOL_INIT(mmu_psize_defs, "mmu_psize_defs"); > >> SYMBOL_INIT(mmu_vmemmap_psize, "mmu_vmemmap_psize"); > >> + SYMBOL_INIT(free_huge_page, "free_huge_page"); > >> > >> SYMBOL_INIT(cpu_pgd, "cpu_pgd"); > >> SYMBOL_INIT(demote_segment_4k, "demote_segment_4k"); > >> @@ -1296,6 +1297,15 @@ get_structure_info(void) > >> ENUM_NUMBER_INIT(PG_slab, "PG_slab"); > >> ENUM_NUMBER_INIT(PG_hwpoison, "PG_hwpoison"); > >> > >> + ENUM_NUMBER_INIT(PG_head_mask, "PG_head_mask"); > >> + if (NUMBER(PG_head_mask) == NOT_FOUND_NUMBER) { > >> + ENUM_NUMBER_INIT(PG_head, "PG_head"); > >> + if (NUMBER(PG_head) == NOT_FOUND_NUMBER) > >> + ENUM_NUMBER_INIT(PG_head, "PG_compound"); > >> + if (NUMBER(PG_head) != NOT_FOUND_NUMBER) > >> + NUMBER(PG_head_mask) = 1UL << NUMBER(PG_head); > >> + } > >> + > >> ENUM_TYPE_SIZE_INIT(pageflags, "pageflags"); > >> > >> TYPEDEF_SIZE_INIT(nodemask_t, "nodemask_t"); > >> @@ -1530,6 +1540,9 @@ get_value_for_old_linux(void) > >> NUMBER(PG_swapcache) = PG_swapcache_ORIGINAL; > >> if (NUMBER(PG_slab) == NOT_FOUND_NUMBER) > >> NUMBER(PG_slab) = PG_slab_ORIGINAL; > >> + if (NUMBER(PG_head_mask) == NOT_FOUND_NUMBER) > >> + NUMBER(PG_head_mask) = 1L << PG_compound_ORIGINAL; > >> + > >> /* > >> * The values from here are for free page filtering based on > >> * mem_map array. These are minimum effort to cover old > >> @@ -1699,6 +1712,7 @@ write_vmcoreinfo_data(void) > >> WRITE_SYMBOL("mmu_vmemmap_psize", mmu_vmemmap_psize); > >> WRITE_SYMBOL("cpu_pgd", cpu_pgd); > >> WRITE_SYMBOL("demote_segment_4k", demote_segment_4k); > >> + WRITE_SYMBOL("free_huge_page", free_huge_page); > >> > >> /* > >> * write the structure size of 1st kernel > >> @@ -1788,6 +1802,7 @@ write_vmcoreinfo_data(void) > >> > >> WRITE_NUMBER("PG_lru", PG_lru); > >> WRITE_NUMBER("PG_private", PG_private); > >> + WRITE_NUMBER("PG_head_mask", PG_head_mask); > >> WRITE_NUMBER("PG_swapcache", PG_swapcache); > >> WRITE_NUMBER("PG_buddy", PG_buddy); > >> WRITE_NUMBER("PG_slab", PG_slab); > >> @@ -2040,6 +2055,7 @@ read_vmcoreinfo(void) > >> READ_SYMBOL("mmu_vmemmap_psize", mmu_vmemmap_psize); > >> READ_SYMBOL("cpu_pgd", cpu_pgd); > >> READ_SYMBOL("demote_segment_4k", demote_segment_4k); > >> + READ_SYMBOL("free_huge_page", free_huge_page); > >> > >> READ_STRUCTURE_SIZE("page", page); > >> READ_STRUCTURE_SIZE("mem_section", mem_section); > >> @@ -2116,6 +2132,7 @@ read_vmcoreinfo(void) > >> > >> READ_NUMBER("PG_lru", PG_lru); > >> READ_NUMBER("PG_private", PG_private); > >> + READ_NUMBER("PG_head_mask", PG_head_mask); > >> READ_NUMBER("PG_swapcache", PG_swapcache); > >> READ_NUMBER("PG_slab", PG_slab); > >> READ_NUMBER("PG_buddy", PG_buddy); > >> @@ -4643,13 +4660,16 @@ __exclude_unnecessary_pages(unsigned long mem_map, > >> mdf_pfn_t pfn_start, mdf_pfn_t pfn_end, struct cycle *cycle) > >> { > >> mdf_pfn_t pfn; > >> + mdf_pfn_t *pfn_counter; > >> + mdf_pfn_t nr_pages; > >> unsigned long index_pg, pfn_mm; > >> unsigned long long maddr; > >> mdf_pfn_t pfn_read_start, pfn_read_end; > >> unsigned char page_cache[SIZE(page) * PGMM_CACHED]; > >> unsigned char *pcache; > >> - unsigned int _count, _mapcount = 0; > >> + unsigned int _count, _mapcount = 0, compound_order = 0; > >> unsigned long flags, mapping, private = 0; > >> + unsigned long compound_dtor; > >> > >> /* > >> * If a multi-page exclusion is pending, do it first > >> @@ -4715,11 +4735,36 @@ __exclude_unnecessary_pages(unsigned long mem_map, > >> flags = ULONG(pcache + OFFSET(page.flags)); > >> _count = UINT(pcache + OFFSET(page._count)); > >> mapping = ULONG(pcache + OFFSET(page.mapping)); > >> + > >> + if ((index_pg < PGMM_CACHED - 1) && > >> + isCompoundHead(flags)) { > >> + compound_order = ULONG(pcache + SIZE(page) + > >> OFFSET(page.lru) > >> + + OFFSET(list_head.prev)); > >> + compound_dtor = ULONG(pcache + SIZE(page) + > >> OFFSET(page.lru) > >> + + OFFSET(list_head.next)); > >> + > >> + if ((compound_order >= sizeof(unsigned long) * 8) > >> + || ((pfn & ((1UL << compound_order) - 1)) != 0)) { > >> + /* Invalid order */ > >> + compound_order = 0; > >> + } > >> + } else { > >> + /* > >> + * The last pfn of the mem_map cache must not be > >> compound page > >> + * since all compound pages are aligned to its page > >> order and > >> + * PGMM_CACHED is a power of 2. > >> + */ > >> + compound_order = 0; > >> + compound_dtor = 0; > >> + } > >> + > >> if (OFFSET(page._mapcount) != NOT_FOUND_STRUCTURE) > >> _mapcount = UINT(pcache + OFFSET(page._mapcount)); > >> if (OFFSET(page.private) != NOT_FOUND_STRUCTURE) > >> private = ULONG(pcache + OFFSET(page.private)); > >> > >> + nr_pages = 1 << compound_order; > >> + pfn_counter = NULL; > >> /* > >> * Exclude the free page managed by a buddy > >> * Use buddy identification of free pages whether cyclic or not. > >> @@ -4727,12 +4772,8 @@ __exclude_unnecessary_pages(unsigned long mem_map, > >> if ((info->dump_level & DL_EXCLUDE_FREE) > >> && info->page_is_buddy > >> && info->page_is_buddy(flags, _mapcount, private, _count)) { > >> - int nr_pages = 1 << private; > >> - > >> - exclude_range(&pfn_free, pfn, pfn + nr_pages, cycle); > >> - > >> - pfn += nr_pages - 1; > >> - mem_map += (nr_pages - 1) * SIZE(page); > >> + nr_pages = 1 << private; > >> + pfn_counter = &pfn_free; > >> } > >> /* > >> * Exclude the cache page without the private page. > >> @@ -4740,8 +4781,7 @@ __exclude_unnecessary_pages(unsigned long mem_map, > >> else if ((info->dump_level & DL_EXCLUDE_CACHE) > >> && (isLRU(flags) || isSwapCache(flags)) > >> && !isPrivate(flags) && !isAnon(mapping)) { > >> - if (clear_bit_on_2nd_bitmap_for_kernel(pfn, cycle)) > >> - pfn_cache++; > >> + pfn_counter = &pfn_cache; > >> } > >> /* > >> * Exclude the cache page with the private page. > >> @@ -4749,23 +4789,39 @@ __exclude_unnecessary_pages(unsigned long mem_map, > >> else if ((info->dump_level & DL_EXCLUDE_CACHE_PRI) > >> && (isLRU(flags) || isSwapCache(flags)) > >> && !isAnon(mapping)) { > >> - if (clear_bit_on_2nd_bitmap_for_kernel(pfn, cycle)) > >> - pfn_cache_private++; > >> + pfn_counter = &pfn_cache_private; > >> } > >> /* > >> * Exclude the data page of the user process. > >> + * - anonymous pages > >> + * - hugetlbfs pages > >> */ > >> else if ((info->dump_level & DL_EXCLUDE_USER_DATA) > >> - && isAnon(mapping)) { > >> - if (clear_bit_on_2nd_bitmap_for_kernel(pfn, cycle)) > >> - pfn_user++; > >> + && (isAnon(mapping) || isHugetlb(compound_dtor))) { > >> + pfn_counter = &pfn_user; > >> } > >> /* > >> * Exclude the hwpoison page. > >> */ > >> else if (isHWPOISON(flags)) { > >> + pfn_counter = &pfn_hwpoison; > >> + } > >> + /* > >> + * Unexcludable page > >> + */ > >> + else > >> + continue; > >> + > >> + /* > >> + * Execute exclusion > >> + */ > >> + if (nr_pages == 1) { > >> if (clear_bit_on_2nd_bitmap_for_kernel(pfn, cycle)) > >> - pfn_hwpoison++; > >> + (*pfn_counter)++; > >> + } else { > >> + exclude_range(pfn_counter, pfn, pfn + nr_pages, cycle); > >> + pfn += nr_pages - 1; > >> + mem_map += (nr_pages - 1) * SIZE(page); > >> } > >> } > >> return TRUE; > >> diff --git a/makedumpfile.h b/makedumpfile.h > >> index eba9798..9f90b53 100644 > >> --- a/makedumpfile.h > >> +++ b/makedumpfile.h > >> @@ -74,6 +74,7 @@ int get_mem_type(void); > >> #define PG_lru_ORIGINAL (5) > >> #define PG_slab_ORIGINAL (7) > >> #define PG_private_ORIGINAL (11) /* Has something at ->private */ > >> +#define PG_compound_ORIGINAL (14) /* Is part of a compound page */ > >> #define PG_swapcache_ORIGINAL (15) /* Swap page: swp_entry_t in > >> private */ > >> > >> #define PAGE_BUDDY_MAPCOUNT_VALUE_v2_6_38 (-2) > >> @@ -148,6 +149,9 @@ test_bit(int nr, unsigned long addr) > >> > >> #define isLRU(flags) test_bit(NUMBER(PG_lru), flags) > >> #define isPrivate(flags) test_bit(NUMBER(PG_private), flags) > >> +#define isCompoundHead(flags) (!!((flags) & NUMBER(PG_head_mask))) > >> +#define isHugetlb(dtor) ((SYMBOL(free_huge_page) != > >> NOT_FOUND_SYMBOL) \ > >> + && (SYMBOL(free_huge_page) == dtor)) > >> #define isSwapCache(flags) test_bit(NUMBER(PG_swapcache), flags) > >> #define isHWPOISON(flags) (test_bit(NUMBER(PG_hwpoison), flags) \ > >> && (NUMBER(PG_hwpoison) != NOT_FOUND_NUMBER)) > >> @@ -1218,6 +1222,7 @@ struct symbol_table { > >> unsigned long long node_remap_start_vaddr; > >> unsigned long long node_remap_end_vaddr; > >> unsigned long long node_remap_start_pfn; > >> + unsigned long long free_huge_page; > >> > >> /* > >> * for Xen extraction > >> @@ -1509,6 +1514,8 @@ struct number_table { > >> */ > >> long PG_lru; > >> long PG_private; > >> + long PG_head; > >> + long PG_head_mask; > >> long PG_swapcache; > >> long PG_buddy; > >> long PG_slab; > >> -- > >> 1.9.0 > >> > >> _______________________________________________ > >> kexec mailing list > >> [email protected] > >> http://lists.infradead.org/mailman/listinfo/kexec _______________________________________________ kexec mailing list [email protected] http://lists.infradead.org/mailman/listinfo/kexec
