Messages in this thread | | | Date | Mon, 01 Sep 2008 15:00:33 +0900 | From | Hidehiro Kawai <> | Subject | Re: [PATCH] coredump_filter: add hugepage core dumping |
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Hi Kosaki-san,
KOSAKI Motohiro wrote:
> Now, hugepage's vma has VM_RESERVED flag because it cannot be swapped. > > and VM_RESERVED vma isn't core dumped because its flag often be used for > kernel internal vma (e.g. vmalloc, sound related). > > So, hugepage is never dumped and it indicate hugepages's program can't be debugged easily. > > In these days, demand on making use of hugepage is increasing. > IMO, native support for coredump of hugepage is useful. > > > I think VM_RESERVED default dumping bahavior is good, > then I'd like to add coredump_filter mask.
> Index: b/Documentation/filesystems/proc.txt > =================================================================== > --- a/Documentation/filesystems/proc.txt > +++ b/Documentation/filesystems/proc.txt > @@ -2389,11 +2389,12 @@ will be dumped when the <pid> process is > of memory types. If a bit of the bitmask is set, memory segments of the > corresponding memory type are dumped, otherwise they are not dumped. > > -The following 4 memory types are supported: > +The following 5 memory types are supported: > - (bit 0) anonymous private memory > - (bit 1) anonymous shared memory > - (bit 2) file-backed private memory > - (bit 3) file-backed shared memory > + - (bit 5) hugetlb memory
Hugetlb VMAs fall also into one of the lowest 4 bit case. If you introduce the hugetlb bit (bit 5), you'd better describe that the hugetlb bit takes precedence over the lowest 4 bits.
Thanks, -- Hidehiro Kawai Hitachi, Systems Development Laboratory Linux Technology Center
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