Pratyush Anand <[email protected]> writes: > On 21/06/2016:05:43:29 AM, Atsushi Kumagai wrote: >> 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 <[email protected]> >> >--- >> >Changes since 'v1': >> >- Make '_refcount' the default [Atsushi Kumagai] > > Sorry, I missed this conversation earlier. > >> >> 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; > > Probably we could have avoided this flag and could have solved it same way as > we > have solved for other such kernel changes, like that of "module.module_core". > Infact, we do not need to add "_refcount" in makedumpfile's page struct. >
Yes, the flag is only needed to do the write. Why do you think we don't need it? > See: > https://github.com/pratyushanand/makedumpfile/commit/8c58c177d27d4ac31db2ee42442ef056dbbd2c93 > > ~Pratyush > >> >+ } >> >+ >> > 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 >> >> >> _______________________________________________ >> kexec mailing list >> [email protected] >> http://lists.infradead.org/mailman/listinfo/kexec -- Vitaly _______________________________________________ kexec mailing list [email protected] http://lists.infradead.org/mailman/listinfo/kexec
