Hello Vitaly,
>_count member was renamed to _refcount in linux commit 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>
Thanks for your report and fixing it.
>---
>- 'crash' tool is now broken as well.
>---
> makedumpfile.c | 18 +++++++++++++++++-
> makedumpfile.h | 1 +
> 2 files changed, 18 insertions(+), 1 deletion(-)
>
>diff --git a/makedumpfile.c b/makedumpfile.c
>index 853b999..96dfe39 100644
>--- a/makedumpfile.c
>+++ b/makedumpfile.c
>@@ -1580,6 +1580,13 @@ get_structure_info(void)
> SIZE_INIT(page, "page");
> OFFSET_INIT(page.flags, "page", "flags");
> OFFSET_INIT(page._count, "page", "_count");
>+ if (OFFSET(page._count) == NOT_FOUND_STRUCTURE) {
>+ info->flag_refcount = TRUE;
>+ OFFSET_INIT(page._count, "page", "_refcount");
>+ } else {
>+ info->flag_refcount = FALSE;
>+ }
>+
I prefer to check the new symbol name first since it's likely
from now on.
> OFFSET_INIT(page.mapping, "page", "mapping");
> OFFSET_INIT(page._mapcount, "page", "_mapcount");
> OFFSET_INIT(page.private, "page", "private");
>@@ -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_refcount)
>+ WRITE_MEMBER_OFFSET("page._refcount", page._count);
>+ else
>+ WRITE_MEMBER_OFFSET("page._count", page._count);
> WRITE_MEMBER_OFFSET("page.mapping", page.mapping);
> WRITE_MEMBER_OFFSET("page.lru", page.lru);
> WRITE_MEMBER_OFFSET("page._mapcount", page._mapcount);
>@@ -2492,6 +2502,12 @@ read_vmcoreinfo(void)
>
> READ_MEMBER_OFFSET("page.flags", page.flags);
> READ_MEMBER_OFFSET("page._count", page._count);
>+ if (OFFSET(page._count) == NOT_FOUND_STRUCTURE) {
>+ info->flag_refcount = TRUE;
>+ READ_MEMBER_OFFSET("page._refcount", page._count);
>+ } else {
>+ info->flag_refcount = FALSE;
>+ }
same as OFFSET_INIT.
Thanks,
Atsushi Kumagai
> READ_MEMBER_OFFSET("page.mapping", page.mapping);
> READ_MEMBER_OFFSET("page.lru", page.lru);
> READ_MEMBER_OFFSET("page._mapcount", page._mapcount);
>diff --git a/makedumpfile.h b/makedumpfile.h
>index 251d4bf..3742389 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_refcount; /* _count is renamed to _refcount */
> unsigned long vaddr_for_vtop; /* virtual address for debugging */
> long page_size; /* size of page */
> long page_shift;
>--
>2.5.5
