Hello Vitaly,
>_count member was renamed to _refcount in linux commit 0139aa7b7fa12
>("mm: rename _count, field of the struct page, to _refcount") and this
>broke makedumpfile. The reason for making the change was to find all users
>accessing it directly and not through the recommended API. I tried
>suggesting to revert the change but failed, I see no other choice than to
>start supporting both _count and _refcount in makedumpfile.
>
>Signed-off-by: Vitaly Kuznetsov <vkuznets at redhat.com>
>---
>Changes since 'v1':
>- Make '_refcount' the default [Atsushi Kumagai]
Good fix, I'll merge this into v1.6.1.
Thanks,
Atsushi Kumagai
>---
> makedumpfile.c | 26 +++++++++++++++++++++-----
> makedumpfile.h | 3 ++-
> 2 files changed, 23 insertions(+), 6 deletions(-)
>
>diff --git a/makedumpfile.c b/makedumpfile.c
>index 853b999..fd884d3 100644
>--- a/makedumpfile.c
>+++ b/makedumpfile.c
>@@ -1579,7 +1579,14 @@ get_structure_info(void)
> */
> SIZE_INIT(page, "page");
> OFFSET_INIT(page.flags, "page", "flags");
>- OFFSET_INIT(page._count, "page", "_count");
>+ OFFSET_INIT(page._refcount, "page", "_refcount");
>+ if (OFFSET(page._refcount) == NOT_FOUND_STRUCTURE) {
>+ info->flag_use_count = TRUE;
>+ OFFSET_INIT(page._refcount, "page", "_count");
>+ } else {
>+ info->flag_use_count = FALSE;
>+ }
>+
> OFFSET_INIT(page.mapping, "page", "mapping");
> OFFSET_INIT(page._mapcount, "page", "_mapcount");
> OFFSET_INIT(page.private, "page", "private");
>@@ -2044,7 +2051,7 @@ get_mem_type(void)
>
> if ((SIZE(page) == NOT_FOUND_STRUCTURE)
> || (OFFSET(page.flags) == NOT_FOUND_STRUCTURE)
>- || (OFFSET(page._count) == NOT_FOUND_STRUCTURE)
>+ || (OFFSET(page._refcount) == NOT_FOUND_STRUCTURE)
> || (OFFSET(page.mapping) == NOT_FOUND_STRUCTURE)) {
> ret = NOT_FOUND_MEMTYPE;
> } else if ((((SYMBOL(node_data) != NOT_FOUND_SYMBOL)
>@@ -2151,7 +2158,10 @@ write_vmcoreinfo_data(void)
> * write the member offset of 1st kernel
> */
> WRITE_MEMBER_OFFSET("page.flags", page.flags);
>- WRITE_MEMBER_OFFSET("page._count", page._count);
>+ if (info->flag_use_count)
>+ WRITE_MEMBER_OFFSET("page._count", page._refcount);
>+ else
>+ WRITE_MEMBER_OFFSET("page._refcount", page._refcount);
> WRITE_MEMBER_OFFSET("page.mapping", page.mapping);
> WRITE_MEMBER_OFFSET("page.lru", page.lru);
> WRITE_MEMBER_OFFSET("page._mapcount", page._mapcount);
>@@ -2491,7 +2501,13 @@ read_vmcoreinfo(void)
>
>
> READ_MEMBER_OFFSET("page.flags", page.flags);
>- READ_MEMBER_OFFSET("page._count", page._count);
>+ READ_MEMBER_OFFSET("page._refcount", page._refcount);
>+ if (OFFSET(page._refcount) == NOT_FOUND_STRUCTURE) {
>+ info->flag_use_count = TRUE;
>+ READ_MEMBER_OFFSET("page._count", page._refcount);
>+ } else {
>+ info->flag_use_count = FALSE;
>+ }
> READ_MEMBER_OFFSET("page.mapping", page.mapping);
> READ_MEMBER_OFFSET("page.lru", page.lru);
> READ_MEMBER_OFFSET("page._mapcount", page._mapcount);
>@@ -5615,7 +5631,7 @@ __exclude_unnecessary_pages(unsigned long mem_map,
> pcache = page_cache + (index_pg * SIZE(page));
>
> flags = ULONG(pcache + OFFSET(page.flags));
>- _count = UINT(pcache + OFFSET(page._count));
>+ _count = UINT(pcache + OFFSET(page._refcount));
> mapping = ULONG(pcache + OFFSET(page.mapping));
>
> if (OFFSET(page.compound_order) != NOT_FOUND_STRUCTURE) {
>diff --git a/makedumpfile.h b/makedumpfile.h
>index 251d4bf..533e5b8 100644
>--- a/makedumpfile.h
>+++ b/makedumpfile.h
>@@ -1100,6 +1100,7 @@ struct DumpInfo {
> int flag_nospace; /* the flag of "No space on device" error */
> int flag_vmemmap; /* kernel supports vmemmap address space */
> int flag_excludevm; /* -e - excluding unused vmemmap pages */
>+ int flag_use_count; /* _refcount is named _count in struct page */
> unsigned long vaddr_for_vtop; /* virtual address for debugging */
> long page_size; /* size of page */
> long page_shift;
>@@ -1483,7 +1484,7 @@ struct size_table {
> struct offset_table {
> struct page {
> long flags;
>- long _count;
>+ long _refcount;
> long mapping;
> long lru;
> long _mapcount;
>--
>2.5.5
