On 2023/12/19 0:01, Huang Shijie wrote: > If the kernel exports the vmmemap then we can use that symbol in > crash to optimize access. vmmemap is just an array of page structs > after all. > > This patch tries to: > 1.) Get the "vmemmap" from the vmcore file. > If we can use the "vmemmap", we implement the arm64_vmemmap_is_page_ptr > and set it to machdep->is_page_ptr. > 2.) We implement the fast page_to_pfn code in arm64_vmemmap_is_page_ptr. > 3.) Dump it in "help -m" > > Test result: > Without the this patch: > #files -p xxx > /dev/null (xxx is the inode of vmlinux which is 441M) > This costed about 185 seconds. > > With the this patch: > #files -p xxx > /dev/null (xxx is the inode of vmlinux which is 441M) > This costed 3 seconds. > > Signed-off-by: Huang Shijie <[email protected]> > --- > v3 --> v4: > Use "files -p" to measure the time. > Dump it in "help -m"
Acked-by: Kazuhito Hagio <[email protected]> Applied the 1/2 first, https://github.com/crash-utility/crash/commit/19d3c56c9fca and will apply this when a corresponding kernel patch gets applied. Thanks, Kazu > --- > arm64.c | 26 ++++++++++++++++++++++++++ > defs.h | 1 + > 2 files changed, 27 insertions(+) > > diff --git a/arm64.c b/arm64.c > index 57965c6..fc4ba64 100644 > --- a/arm64.c > +++ b/arm64.c > @@ -117,6 +117,28 @@ static void arm64_calc_kernel_start(void) > ms->kimage_end = (sp ? sp->value : 0); > } > > +static int > +arm64_vmemmap_is_page_ptr(ulong addr, physaddr_t *phys) > +{ > + ulong size = SIZE(page); > + ulong pfn, nr; > + > + > + if (IS_SPARSEMEM() && (machdep->flags & VMEMMAP) && > + (addr >= VMEMMAP_VADDR && addr <= VMEMMAP_END) && > + !((addr - VMEMMAP_VADDR) % size)) { > + > + pfn = (addr - machdep->machspec->vmemmap) / size; > + nr = pfn_to_section_nr(pfn); > + if (valid_section_nr(nr)) { > + if (phys) > + *phys = PTOB(pfn); > + return TRUE; > + } > + } > + return FALSE; > +} > + > /* > * Do all necessary machine-specific setup here. This is called several > times > * during initialization. > @@ -382,6 +404,9 @@ arm64_init(int when) > > machdep->stacksize = ARM64_STACK_SIZE; > machdep->flags |= VMEMMAP; > + /* If vmemmap exists, it means kernel enabled > CONFIG_SPARSEMEM_VMEMMAP */ > + if (arm64_get_vmcoreinfo(&ms->vmemmap, "SYMBOL(vmemmap)", > NUM_HEX)) > + machdep->is_page_ptr = arm64_vmemmap_is_page_ptr; > > machdep->uvtop = arm64_uvtop; > machdep->is_uvaddr = arm64_is_uvaddr; > @@ -1096,6 +1121,7 @@ arm64_dump_machdep_table(ulong arg) > fprintf(fp, " vmemmap_vaddr: %016lx\n", ms->vmemmap_vaddr); > fprintf(fp, " vmemmap_end: %016lx\n", ms->vmemmap_end); > if (machdep->flags & NEW_VMEMMAP) { > + fprintf(fp, " vmemmap: %016lx\n", ms->vmemmap); > fprintf(fp, " kimage_text: %016lx\n", > ms->kimage_text); > fprintf(fp, " kimage_end: %016lx\n", ms->kimage_end); > fprintf(fp, " kimage_voffset: %016lx\n", > ms->kimage_voffset); > diff --git a/defs.h b/defs.h > index 0558d13..3431a32 100644 > --- a/defs.h > +++ b/defs.h > @@ -3486,6 +3486,7 @@ struct machine_specific { > ulong CONFIG_ARM64_KERNELPACMASK; > ulong physvirt_offset; > ulong struct_page_size; > + ulong vmemmap; > }; > > struct arm64_stackframe { -- Crash-utility mailing list -- [email protected] To unsubscribe send an email to [email protected] https://${domain_name}/admin/lists/devel.lists.crash-utility.osci.io/ Contribution Guidelines: https://github.com/crash-utility/crash/wiki
