FEX-Emu/linux
1
0
Fork 0
mirror of https://github.com/FEX-Emu/linux.git synced 2024-12-16 05:50:19 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

kexec: save PG_head_mask in VMCOREINFO

Browse Source 
To allow filtering of huge pages, makedumpfile must be able to identify
them in the dump.  This can be done by checking the appropriate page
flag, so communicate its value to makedumpfile through the VMCOREINFO
interface.

There's only one small catch.  Depending on how many page flags are
available on a given architecture, this bit can be called PG_head or
PG_compound.

I sent a similar patch back in 2012, but Eric Biederman did not like
using an #ifdef.  So, this time I'm adding a common symbol
(PG_head_mask) instead.

See https://lkml.org/lkml/2012/11/28/91 for the previous version.

Signed-off-by: Petr Tesarik <ptesarik@suse.cz>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Alexey Kardashevskiy <aik@ozlabs.ru>
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Petr Tesarik 2014-06-23 13:22:03 -07:00 committed by Linus Torvalds
parent 8d056c48e4
commit b3acc56bfe
2 changed files with 4 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
include/linux/page-flags.h
View File

@ -360,6 +360,9 @@ static inline void ClearPageCompound(struct page *page)
ClearPageHead(page);
}
#endif
#define PG_head_mask ((1L << PG_head))
#else
/*
* Reduce page flag use as much as possible by overlapping

1
kernel/kexec.c
View File

@ -1617,6 +1617,7 @@ static int __init crash_save_vmcoreinfo_init(void)
#ifdef CONFIG_MEMORY_FAILURE
VMCOREINFO_NUMBER(PG_hwpoison);
#endif
VMCOREINFO_NUMBER(PG_head_mask);
VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
arch_crash_save_vmcoreinfo();