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    SubjectRE: [PATCH 1/2 v4] kdump: add the vmcoreinfo documentation
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    -----Original Message-----
    > >> +=======================
    > >> +What is the VMCOREINFO?
    > >> +=======================
    > >> +
    > >> +VMCOREINFO is a special ELF note section. It contains various
    > >> +information from the kernel like structure size, page size, symbol
    > >> +values, field offsets, etc. These data are packed into an ELF note
    > >> +section and used by user-space tools like crash and makedumpfile to
    > >> +analyze a kernel's memory layout.
    > >> +
    > >> +To dump the VMCOREINFO contents, one can do:
    > >> +
    > >> +# makedumpfile -g VMCOREINFO -x vmlinux
    > >
    > > again, this command does not dump the VMCOREINFO in ELF note section.
    > > It converts the vmlinux's debug infomation into a VMCOREINFO-like data.
    > > So I don't think this command is suitable to introduce here.
    > >
    >
    > Thank you, Kazu.
    >
    > As you mentioned, makedumpfile in 'devel' branch can print VMCOREINFO in /proc/kcore,
    > can i add the following command to this document?
    >
    > #makedumpfile --mem-usage /proc/kcore -D

    I don't know whether we can add unreleased softwares to the document.
    Any comments on this?

    If it's OK, crash also can dump it, so
    ---
    To dump the VMCOREINFO contents, one can do:

    # crash vmlinux /proc/kcore
    ...
    > help -n
    or
    # makedumpfile -D --mem-usage /proc/kcore
    ---

    or remove that for now and update later?

    >
    > >> +PG_lru|PG_private|PG_swapcache|PG_swapbacked|PG_slab|
    > >> +PG_hwpoision|PG_head_mask
    > >> +-----------------------------------------------------
    > >> +
    > >> +Page attributes. These flags are used to filter free pages.
    > >
    > > Some of these are not used to filter *free* pages, so
    > >
    > > ... used to filter various unnecessary pages.
    > >
    >
    > Great. I will modify it in next post.
    >
    > And also merge the 'PG_buddy' and 'PG_offline' into the PG_* flag here.

    Thanks, I think your "PAGE_OFFLINE_MAPCOUNT_VALUE(~PG_offline)" style is good.

    Kazu

    >
    > Many thanks.
    >
    > Lianbo
    >
    > >> +PAGE_BUDDY_MAPCOUNT_VALUE or ~PG_buddy
    > >> +--------------------------------------
    > >
    > > then, this can be merged into the one above?
    > >
    > >> +======
    > >> +x86_64
    > >> +======
    > > ...
    > >> +PAGE_OFFLINE_MAPCOUNT_VALUE(~PG_offline)
    > >> +----------------------------------------
    > >
    > > This looks not only for x86_64, and also can be merged into
    > > the PG_* flags?
    > >
    > > Thank you for your effort!
    > > Kazu
    > >
    > >


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