[PATCH] makedumpfile/arm64: Add '--mem-usage' support
Masaki Tachibana
mas-tachibana at vf.jp.nec.com
Thu Mar 1 21:31:59 PST 2018
Hi Bhupesh,
Sorry for the late reply.
And thank you for your patch.
I have some questions. Please answer me.
- Have you succeeded --mem-usage on ppc64, s390x ?
- By your patch, makedumpfile behaves like this;
1.Gets an address of _stext from a vmlinux file.
2.Checks how many upper bits are 1 in the address.
3.Determines va_bits and info->page_offset by the check.
Isn't there any other method to get page_offset without a vmlinux ?
Thanks
Tachibana
> -----Original Message-----
> From: kexec [mailto:kexec-bounces at lists.infradead.org] On Behalf Of Bhupesh SHARMA
> Sent: Thursday, February 22, 2018 3:58 AM
> To: Tachibana Masaki() <mas-tachibana at vf.jp.nec.com>
> Cc: kexec at lists.infradead.org; Bhupesh Sharma <bhsharma at redhat.com>; Hayashi Masahiko()
> <mas-hayashi at tg.jp.nec.com>
> Subject: Re: [PATCH] makedumpfile/arm64: Add '--mem-usage' support
>
> Hi Masaki Tachibana,
>
> On Tue, Feb 20, 2018 at 4:42 PM, Masaki Tachibana
> <mas-tachibana at vf.jp.nec.com> wrote:
> > Hi Bhupesh,
> >
> > Sorry for the late reply.
> > I'll reply by the end the next week.
>
> Sure. Thanks for your mail.
>
> Regards,
> Bhupesh
>
>
> > Thanks
> > tachibana
> >
> >> -----Original Message-----
> >> From: Bhupesh Sharma [mailto:bhsharma at redhat.com]
> >> Sent: Tuesday, February 20, 2018 1:56 PM
> >> To: kexec at lists.infradead.org
> >> Cc: Bhupesh Sharma <bhsharma at redhat.com>; Tachibana Masaki() <mas-tachibana at vf.jp.nec.com>; Nakayama Takuya(
> >> ) <tak-nakayama at tg.jp.nec.com>; Nishimura Daisuke() <dai-nishimura at rc.jp.nec.com>
> >> Subject: Re: [PATCH] makedumpfile/arm64: Add '--mem-usage' support
> >>
> >> Hello,
> >>
> >> On Fri, Feb 9, 2018 at 3:06 PM, Bhupesh Sharma <bhsharma at redhat.com> wrote:
> >> > Its good to have the makedumpfile '--mem-usage' support
> >> > for arm64 architecture as well, as it allows one to see the page numbers
> >> > of current system (1st kernel) in different use.
> >> >
> >> > Using this we can know how many pages are dumpable when different
> >> > dump_level is specified.
> >> >
> >> > Normally for x86_64, makedumpfile analyzes the 'System Ram' and
> >> > 'kernel text' program segment of /proc/kcore excluding
> >> > the crashkernel range, then calculates the page number of different
> >> > kind per vmcoreinfo.
> >> >
> >> > We use the similar logic for arm64, but in addition make the '--mem-usage'
> >> > usage dependent on the VMLINUX file being passed. This is done to allow
> >> > information like VA_BITS being determined from kernel symbol like
> >> > _stext. This allows us to get the VA_BITS before 'set_kcore_vmcoreinfo()'
> >> > is called.
> >> >
> >> > Also I have validated the '--mem-usage' makedumpfile option on several
> >> > ppc64/ppc64le and s390x machines, so update the makedumpfile.8
> >> > documentation to indicate that '--mem-usage' option is supported
> >> > not only on x86_64, but also on ppc64, s390x and arm64.
> >> >
> >> > After this patch, when using the '--mem-usage' option with makedumpfile,
> >> > we get the correct information about the different pages. For e.g.
> >> > here is an output from my arm64 board:
> >> >
> >> > TYPE PAGES EXCLUDABLE DESCRIPTION
> >> > ----------------------------------------------------------------------
> >> > ZERO 49524 yes Pages filled with zero
> >> > NON_PRI_CACHE 15143 yes Cache pages without private flag
> >> > PRI_CACHE 29147 yes Cache pages with private flag
> >> > USER 3684 yes User process pages
> >> > FREE 1450569 yes Free pages
> >> > KERN_DATA 14243 no Dumpable kernel data
> >> >
> >> > page size: 65536
> >> > Total pages on system: 1562310
> >> > Total size on system: 102387548160 Byte
> >> >
> >> > Cc: Masaki Tachibana <mas-tachibana at vf.jp.nec.com>
> >> > Cc: Takuya Nakayama <tak-nakayama at tg.jp.nec.com>
> >> > Cc: Daisuke Nishimura <dai-nishimura at rc.jp.nec.com>
> >> > Signed-off-by: Bhupesh Sharma <bhsharma at redhat.com>
> >>
> >> Ping. Any review comments on this?
> >>
> >> Regards,
> >> Bhupesh
> >>
> >> > ---
> >> > arch/arm64.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++++---
> >> > makedumpfile.8 | 11 +++++++++--
> >> > makedumpfile.c | 25 +++++++++++++++++++++++--
> >> > makedumpfile.h | 1 +
> >> > 4 files changed, 81 insertions(+), 7 deletions(-)
> >> >
> >> > diff --git a/arch/arm64.c b/arch/arm64.c
> >> > index 25d7a1f4db98..91f113f6447c 100644
> >> > --- a/arch/arm64.c
> >> > +++ b/arch/arm64.c
> >> > @@ -48,6 +48,12 @@ static unsigned long kimage_voffset;
> >> > #define SZ_64K (64 * 1024)
> >> > #define SZ_128M (128 * 1024 * 1024)
> >> >
> >> > +#define PAGE_OFFSET_36 ((0xffffffffffffffffUL) << 36)
> >> > +#define PAGE_OFFSET_39 ((0xffffffffffffffffUL) << 39)
> >> > +#define PAGE_OFFSET_42 ((0xffffffffffffffffUL) << 42)
> >> > +#define PAGE_OFFSET_47 ((0xffffffffffffffffUL) << 47)
> >> > +#define PAGE_OFFSET_48 ((0xffffffffffffffffUL) << 48)
> >> > +
> >> > #define pgd_val(x) ((x).pgd)
> >> > #define pud_val(x) (pgd_val((x).pgd))
> >> > #define pmd_val(x) (pud_val((x).pud))
> >> > @@ -140,8 +146,6 @@ pud_offset(pgd_t *pgda, pgd_t *pgdv, unsigned long vaddr)
> >> >
> >> > static int calculate_plat_config(void)
> >> > {
> >> > - va_bits = NUMBER(VA_BITS);
> >> > -
> >> > /* derive pgtable_level as per arch/arm64/Kconfig */
> >> > if ((PAGESIZE() == SZ_16K && va_bits == 36) ||
> >> > (PAGESIZE() == SZ_64K && va_bits == 42)) {
> >> > @@ -188,7 +192,6 @@ get_machdep_info_arm64(void)
> >> > kimage_voffset = NUMBER(kimage_voffset);
> >> > info->max_physmem_bits = PHYS_MASK_SHIFT;
> >> > info->section_size_bits = SECTIONS_SIZE_BITS;
> >> > - info->page_offset = 0xffffffffffffffffUL << (va_bits - 1);
> >> >
> >> > DEBUG_MSG("kimage_voffset : %lx\n", kimage_voffset);
> >> > DEBUG_MSG("max_physmem_bits : %lx\n", info->max_physmem_bits);
> >> > @@ -219,6 +222,48 @@ get_xen_info_arm64(void)
> >> > int
> >> > get_versiondep_info_arm64(void)
> >> > {
> >> > + unsigned long long stext;
> >> > +
> >> > + /* We can read the _stext symbol from vmlinux and determine the
> >> > + * VA_BITS and page_offset.
> >> > + */
> >> > +
> >> > + /* Open the vmlinux file */
> >> > + open_kernel_file();
> >> > + set_dwarf_debuginfo("vmlinux", NULL,
> >> > + info->name_vmlinux, info->fd_vmlinux);
> >> > +
> >> > + if (!get_symbol_info())
> >> > + return FALSE;
> >> > +
> >> > + /* Get the '_stext' symbol */
> >> > + if (SYMBOL(_stext) == NOT_FOUND_SYMBOL) {
> >> > + ERRMSG("Can't get the symbol of _stext.\n");
> >> > + return FALSE;
> >> > + } else {
> >> > + stext = SYMBOL(_stext);
> >> > + }
> >> > +
> >> > + /* Derive va_bits as per arch/arm64/Kconfig */
> >> > + if ((stext & PAGE_OFFSET_36) == PAGE_OFFSET_36) {
> >> > + va_bits = 36;
> >> > + } else if ((stext & PAGE_OFFSET_39) == PAGE_OFFSET_39) {
> >> > + va_bits = 39;
> >> > + } else if ((stext & PAGE_OFFSET_42) == PAGE_OFFSET_42) {
> >> > + va_bits = 42;
> >> > + } else if ((stext & PAGE_OFFSET_47) == PAGE_OFFSET_47) {
> >> > + va_bits = 47;
> >> > + } else if ((stext & PAGE_OFFSET_48) == PAGE_OFFSET_48) {
> >> > + va_bits = 48;
> >> > + } else {
> >> > + ERRMSG("Cannot find a proper _stext for calculating VA_BITS\n");
> >> > + return FALSE;
> >> > + }
> >> > +
> >> > + info->page_offset = (0xffffffffffffffffUL) << (va_bits - 1);
> >> > +
> >> > + DEBUG_MSG("page_offset=%lx, va_bits=%d\n", info->page_offset, va_bits);
> >> > +
> >> > return TRUE;
> >> > }
> >> >
> >> > diff --git a/makedumpfile.8 b/makedumpfile.8
> >> > index 15db7947d62f..be9620035316 100644
> >> > --- a/makedumpfile.8
> >> > +++ b/makedumpfile.8
> >> > @@ -593,7 +593,7 @@ last cleared on the crashed kernel, through "dmesg --clear" for example.
> >> >
> >> > .TP
> >> > \fB\-\-mem-usage\fR
> >> > -This option is only for x86_64.
> >> > +This option is currently supported on x86_64, arm64, ppc64 and s390x.
> >> > This option is used to show the page numbers of current system in different
> >> > use. It should be executed in 1st kernel. By the help of this, user can know
> >> > how many pages is dumpable when different dump_level is specified. It analyzes
> >> > @@ -601,12 +601,19 @@ the 'System Ram' and 'kernel text' program segment of /proc/kcore excluding
> >> > the crashkernel range, then calculates the page number of different kind per
> >> > vmcoreinfo. So currently /proc/kcore need be specified explicitly.
> >> >
> >> > +For arm64, path to vmlinux file should be specified as well.
> >> > +
> >> > .br
> >> > -.B Example:
> >> > +.B Example (for architectures other than arm64):
> >> > .br
> >> > # makedumpfile \-\-mem-usage /proc/kcore
> >> > +
> >> > +.br
> >> > +.B Example (for arm64 architecture):
> >> > .br
> >> >
> >> > +# makedumpfile \-\-mem-usage vmlinux /proc/kcore
> >> > +.br
> >> >
> >> > .TP
> >> > \fB\-\-diskset=VMCORE\fR
> >> > diff --git a/makedumpfile.c b/makedumpfile.c
> >> > index ed138d339d9a..b38b5000aa74 100644
> >> > --- a/makedumpfile.c
> >> > +++ b/makedumpfile.c
> >> > @@ -11090,7 +11090,14 @@ static struct option longopts[] = {
> >> > {"cyclic-buffer", required_argument, NULL, OPT_CYCLIC_BUFFER},
> >> > {"eppic", required_argument, NULL, OPT_EPPIC},
> >> > {"non-mmap", no_argument, NULL, OPT_NON_MMAP},
> >> > +#ifdef __aarch64__
> >> > + /* VMLINUX file is required for aarch64 for get
> >> > + * the symbols required to calculate va_bits.
> >> > + */
> >> > + {"mem-usage", required_argument, NULL, OPT_MEM_USAGE},
> >> > +#else
> >> > {"mem-usage", no_argument, NULL, OPT_MEM_USAGE},
> >> > +#endif
> >> > {"splitblock-size", required_argument, NULL, OPT_SPLITBLOCK_SIZE},
> >> > {"work-dir", required_argument, NULL, OPT_WORKING_DIR},
> >> > {"num-threads", required_argument, NULL, OPT_NUM_THREADS},
> >> > @@ -11201,8 +11208,22 @@ main(int argc, char *argv[])
> >> > info->flag_partial_dmesg = 1;
> >> > break;
> >> > case OPT_MEM_USAGE:
> >> > - info->flag_mem_usage = 1;
> >> > - break;
> >> > + info->flag_mem_usage = 1;
> >> > +#ifdef __aarch64__
> >> > + /* VMLINUX file is required for aarch64 for get
> >> > + * the symbols required to calculate va_bits and
> >> > + * it should be the 1st command parameter being
> >> > + * specified.
> >> > + */
> >> > + if (strcmp(optarg, "/proc/kcore") == 0) {
> >> > + MSG("vmlinux path should be 1st commandline parameter with --mem-usage option.\n");
> >> > + goto out;
> >> > + }
> >> > + else {
> >> > + info->name_vmlinux = optarg;
> >> > + }
> >> > +#endif
> >> > + break;
> >> > case OPT_COMPRESS_SNAPPY:
> >> > info->flag_compress = DUMP_DH_COMPRESSED_SNAPPY;
> >> > break;
> >> > diff --git a/makedumpfile.h b/makedumpfile.h
> >> > index 01eece231475..f65d91870b73 100644
> >> > --- a/makedumpfile.h
> >> > +++ b/makedumpfile.h
> >> > @@ -2308,6 +2308,7 @@ struct elf_prstatus {
> >> > /*
> >> > * Function Prototype.
> >> > */
> >> > +int open_kernel_file(void);
> >> > mdf_pfn_t get_num_dumpable_cyclic(void);
> >> > mdf_pfn_t get_num_dumpable_cyclic_withsplit(void);
> >> > int get_loads_dumpfile_cyclic(void);
> >> > --
> >> > 2.7.4
> >> >
> >
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