[PATCH v6 0/8] add a new interface to show the memory usage of 1st kernel

[Atsushi Kumagai]

Hello Baoquan,

>Recently people complained that they don't know how to decide how
>much disk size need be reserved for kdump. E.g there are lots of
>machines with different memory size, if the memory usage information
>of current system can be shown, that can help them to make an estimate
>how much storage space need be reserved.
>
>In this patchset, a new interface is added into makedumpfile. By the
>help of this, people can know the page number of memory in different
>use. The implementation is analyzing the "System Ram" and "kernel text"
>program segment of /proc/kcore excluding the crashkernel range, then
>calculating the page number of different kind per vmcoreinfo.
>
>Previouly, patchset v1 was posted. And patch 7/7 has a change in v2.
>So several changes are made in this v3 post per comments from Vivek
>and Atsushi.
>
>[patch 2/8] functions to get crashkernel memory range
>v3->v4:
>    In old iomem_for_each_line(), it will call exit(1) if opening iomem
>    failed. Atsushi suggested changing this to be consistent with other
>    return value. So here change all the return value to be nr, then
>    check it outside of iomem_for_each_line, and then decide how to act.
>
>[patch 3/8] preparation functions for parsing vmcoreinfo
>v1->v3:
>    Since get_kernel_version need be called to get page_offset
>    before initial() in mem_usage code flow, and surely it will be called
>    inside initial() again. Add a static variable to avoid this duplicate
>    calling.
>v3->v4:
>    Check the value of info->kernel_version, just return if it has been
>    assigned to a value. This is suggested by Atsushi, far better than the
>    static variable idea.
>    And replace replace get_versiondep_info_x86_64() with get_versiondep_info
>    in get_page_offset().
>v4->v5:
>    Update the git log.
>
>[patch 4/8] set vmcoreinfo for kcore
>v3->v4:
>    Change several places error messages which are the same in nearby handling.
>
>[patch 5/8] prepare the dump loads for kcore analysis
>v1->v3:
>    Fix the compiler warnings.
>v3->v4:
>    Rename is_vmalloc_addr() to is_vmalloc_addr_x86_64() in arch/x86_64.c. And
>    then define is_vmalloc_addr() for all other ARCHs, just set their value to
>    be TRUE except of x86_64.
>
>[patch 6/8] introduce-a-function-exclude_zero_pages_cyclic
>v3->v4:
>    Newly introduce a function exclude_zero_pages_cyclic(), and call it in
>    get_num_dumpable_cyclic().
>
>    Besides, a strange thing happened when the new interface was tested on
>    my local AMD machine. It always terminated and printed message:
>    "Program terminated with signal SIGKILL"
>    With gdb, it should be going in readmem() of exclude_zero_pages_cyclic, I
>    still don't know why it happened.

This issue is still under investigation, but it may be a kernel issue
since you just read a page of System RAM via /proc/kcore. At least your
patches look good to me, I'll merge them into v1.5.7. Good job!


Thanks
Atsushi Kumagai

>
>[patch 7/8] implement a function to print the memory usage
>v1->v3:
>    Adjust the printing content and format of dumpable page numbers per Vivek's
>    comments.
>v3->v6:
>    Slightly adjust the printing format and content.
>
>[patch 8/8]
>v1->v2:
>    Set info->dump_level=MAX_DUMP_LEVEL, with MAX_DUMP_LEVEL all kinds of
>    memory can be calculated.
>v2->v3:
>    Add the description of this feature into help message and man page.
>v3->v4:
>    Continue adjusting the output message of show_mem_usage calling per
>    Vivek's comments.
>v4->v5:
>    Update the git log.
>v5->v6:
>    Adjust the printing format which is related to dump files previously.
>
>Baoquan He (8):
>  initialize pfn_memhole in get_num_dumpable_cyclic
>  functions to get crashkernel memory range
>  preparation functions for parsing vmcoreinfo
>  set vmcoreinfo for kcore
>  prepare the dump loads for kcore analysis
>  introduce a function exclude_zero_pages_cyclic()
>  implement a function to print the memory usage
>  add a new interface to show the memory usage of 1st kernel
>
> arch/x86_64.c  |   6 +-
> elf_info.c     | 237 +++++++++++++++++++++++++++++++++++++++++++++++
> elf_info.h     |   3 +
> makedumpfile.8 |  17 ++++
> makedumpfile.c | 285 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
> makedumpfile.h |  17 ++++
> print_info.c   |   8 ++
> 7 files changed, 569 insertions(+), 4 deletions(-)
>
>--
>1.8.5.3