From a0eceb041dfa248d66f9f9a455106184b7823bec Mon Sep 17 00:00:00 2001 From: Rongwei Wang Date: Mon, 29 May 2023 19:55:51 +0800 Subject: [PATCH 4/6] arm64/x86_64: Enhance "vtop" command to show zero_pfn information Enhance the "vtop" command to show "ZERO PAGE" information when PTE or PMD has attached to {huge_}zero_pfn. For example: crash> vtop -c 13674 ffff8917e000 VIRTUAL PHYSICAL ffff8917e000 836e71000 PAGE DIRECTORY: ffff000802f8d000 PGD: ffff000802f8dff8 => 884e29003 PUD: ffff000844e29ff0 => 884e93003 PMD: ffff000844e93240 => 840413003 PTE: ffff000800413bf0 => 160000836e71fc3 PAGE: 836e71000 (ZERO PAGE) ... Hugepage case: crash> vtop -c 14538 ffff95800000 VIRTUAL PHYSICAL ffff95800000 910c00000 PAGE DIRECTORY: ffff000801fa0000 PGD: ffff000801fa0ff8 => 884f53003 PUD: ffff000844f53ff0 => 8426cb003 PMD: ffff0008026cb560 => 60000910c00fc1 PAGE: 910c00000 (2MB, ZERO PAGE) ... Note that 1. support displaying zero page only for THP (except for 1G THP) 2. do not support hugetlb cases. Signed-off-by: Rongwei Wang Signed-off-by: Kazuhito Hagio Signed-off-by: Lianbo Jiang --- arm64.c | 24 ++++++++++++++++-------- defs.h | 5 +++++ memory.c | 23 +++++++++++++++++++++++ x86_64.c | 9 +++++---- 4 files changed, 49 insertions(+), 12 deletions(-) diff --git a/arm64.c b/arm64.c index 56fb841f43f8..efbdccbec9d3 100644 --- a/arm64.c +++ b/arm64.c @@ -1787,7 +1787,8 @@ arm64_vtop_2level_64k(ulong pgd, ulong vaddr, physaddr_t *paddr, int verbose) if ((pgd_val & PMD_TYPE_MASK) == PMD_TYPE_SECT) { ulong sectionbase = (pgd_val & SECTION_PAGE_MASK_512MB) & PHYS_MASK; if (verbose) { - fprintf(fp, " PAGE: %lx (512MB)\n\n", sectionbase); + fprintf(fp, " PAGE: %lx (512MB%s)\n\n", sectionbase, + IS_ZEROPAGE(sectionbase) ? ", ZERO PAGE" : ""); arm64_translate_pte(pgd_val, 0, 0); } *paddr = sectionbase + (vaddr & ~SECTION_PAGE_MASK_512MB); @@ -1806,7 +1807,8 @@ arm64_vtop_2level_64k(ulong pgd, ulong vaddr, physaddr_t *paddr, int verbose) if (pte_val & PTE_VALID) { *paddr = (PAGEBASE(pte_val) & PHYS_MASK) + PAGEOFFSET(vaddr); if (verbose) { - fprintf(fp, " PAGE: %lx\n\n", PAGEBASE(*paddr)); + fprintf(fp, " PAGE: %lx %s\n\n", PAGEBASE(*paddr), + IS_ZEROPAGE(PAGEBASE(*paddr)) ? "(ZERO PAGE)" : ""); arm64_translate_pte(pte_val, 0, 0); } } else { @@ -1859,7 +1861,8 @@ arm64_vtop_3level_64k(ulong pgd, ulong vaddr, physaddr_t *paddr, int verbose) if ((pmd_val & PMD_TYPE_MASK) == PMD_TYPE_SECT) { ulong sectionbase = PTE_TO_PHYS(pmd_val) & SECTION_PAGE_MASK_512MB; if (verbose) { - fprintf(fp, " PAGE: %lx (512MB)\n\n", sectionbase); + fprintf(fp, " PAGE: %lx (512MB%s)\n\n", sectionbase, + IS_ZEROPAGE(sectionbase) ? ", ZERO PAGE" : ""); arm64_translate_pte(pmd_val, 0, 0); } *paddr = sectionbase + (vaddr & ~SECTION_PAGE_MASK_512MB); @@ -1878,7 +1881,8 @@ arm64_vtop_3level_64k(ulong pgd, ulong vaddr, physaddr_t *paddr, int verbose) if (pte_val & PTE_VALID) { *paddr = PTE_TO_PHYS(pte_val) + PAGEOFFSET(vaddr); if (verbose) { - fprintf(fp, " PAGE: %lx\n\n", PAGEBASE(*paddr)); + fprintf(fp, " PAGE: %lx %s\n\n", PAGEBASE(*paddr), + IS_ZEROPAGE(PAGEBASE(*paddr)) ? "(ZERO PAGE)" : ""); arm64_translate_pte(pte_val, 0, 0); } } else { @@ -1940,7 +1944,8 @@ arm64_vtop_3level_4k(ulong pgd, ulong vaddr, physaddr_t *paddr, int verbose) if ((pmd_val & PMD_TYPE_MASK) == PMD_TYPE_SECT) { ulong sectionbase = (pmd_val & SECTION_PAGE_MASK_2MB) & PHYS_MASK; if (verbose) { - fprintf(fp, " PAGE: %lx (2MB)\n\n", sectionbase); + fprintf(fp, " PAGE: %lx (2MB%s)\n\n", sectionbase, + IS_ZEROPAGE(sectionbase) ? ", ZERO PAGE" : ""); arm64_translate_pte(pmd_val, 0, 0); } *paddr = sectionbase + (vaddr & ~SECTION_PAGE_MASK_2MB); @@ -1959,7 +1964,8 @@ arm64_vtop_3level_4k(ulong pgd, ulong vaddr, physaddr_t *paddr, int verbose) if (pte_val & PTE_VALID) { *paddr = (PAGEBASE(pte_val) & PHYS_MASK) + PAGEOFFSET(vaddr); if (verbose) { - fprintf(fp, " PAGE: %lx\n\n", PAGEBASE(*paddr)); + fprintf(fp, " PAGE: %lx %s\n\n", PAGEBASE(*paddr), + IS_ZEROPAGE(PAGEBASE(*paddr)) ? "(ZERO PAGE)" : ""); arm64_translate_pte(pte_val, 0, 0); } } else { @@ -2029,7 +2035,8 @@ arm64_vtop_4level_4k(ulong pgd, ulong vaddr, physaddr_t *paddr, int verbose) if ((pmd_val & PMD_TYPE_MASK) == PMD_TYPE_SECT) { ulong sectionbase = (pmd_val & SECTION_PAGE_MASK_2MB) & PHYS_MASK; if (verbose) { - fprintf(fp, " PAGE: %lx (2MB)\n\n", sectionbase); + fprintf(fp, " PAGE: %lx (2MB%s)\n\n", sectionbase, + IS_ZEROPAGE(sectionbase) ? ", ZERO PAGE" : ""); arm64_translate_pte(pmd_val, 0, 0); } *paddr = sectionbase + (vaddr & ~SECTION_PAGE_MASK_2MB); @@ -2048,7 +2055,8 @@ arm64_vtop_4level_4k(ulong pgd, ulong vaddr, physaddr_t *paddr, int verbose) if (pte_val & PTE_VALID) { *paddr = (PAGEBASE(pte_val) & PHYS_MASK) + PAGEOFFSET(vaddr); if (verbose) { - fprintf(fp, " PAGE: %lx\n\n", PAGEBASE(*paddr)); + fprintf(fp, " PAGE: %lx %s\n\n", PAGEBASE(*paddr), + IS_ZEROPAGE(PAGEBASE(*paddr)) ? "(ZERO PAGE)" : ""); arm64_translate_pte(pte_val, 0, 0); } } else { diff --git a/defs.h b/defs.h index bfa07c3f5150..7d8bb8ab3de1 100644 --- a/defs.h +++ b/defs.h @@ -2619,6 +2619,8 @@ struct vm_table { /* kernel VM-related data */ char *name; } *pageflags_data; ulong max_mem_section_nr; + ulong zero_paddr; + ulong huge_zero_paddr; }; #define NODES (0x1) @@ -3000,6 +3002,9 @@ struct load_module { #define VIRTPAGEBASE(X) (((ulong)(X)) & (ulong)machdep->pagemask) #define PHYSPAGEBASE(X) (((physaddr_t)(X)) & (physaddr_t)machdep->pagemask) +#define IS_ZEROPAGE(paddr) ((paddr) == vt->zero_paddr || \ + (paddr) == vt->huge_zero_paddr) + /* * Sparse memory stuff * These must follow the definitions in the kernel mmzone.h diff --git a/memory.c b/memory.c index 15fa8b2f08f1..ea3005a5c01f 100644 --- a/memory.c +++ b/memory.c @@ -1209,6 +1209,27 @@ vm_init(void) machdep->memory_size())); vt->paddr_prlen = strlen(buf); + vt->zero_paddr = ~0UL; + if (kernel_symbol_exists("zero_pfn")) { + ulong zero_pfn; + + if (readmem(symbol_value("zero_pfn"), KVADDR, + &zero_pfn, sizeof(zero_pfn), + "read zero_pfn", QUIET|RETURN_ON_ERROR)) + vt->zero_paddr = zero_pfn << PAGESHIFT(); + } + + vt->huge_zero_paddr = ~0UL; + if (kernel_symbol_exists("huge_zero_pfn")) { + ulong huge_zero_pfn; + + if (readmem(symbol_value("huge_zero_pfn"), KVADDR, + &huge_zero_pfn, sizeof(huge_zero_pfn), + "read huge_zero_pfn", QUIET|RETURN_ON_ERROR) && + huge_zero_pfn != ~0UL) + vt->huge_zero_paddr = huge_zero_pfn << PAGESHIFT(); + } + if (vt->flags & PERCPU_KMALLOC_V1) vt->dump_kmem_cache = dump_kmem_cache_percpu_v1; else if (vt->flags & PERCPU_KMALLOC_V2) @@ -14065,6 +14086,8 @@ dump_vm_table(int verbose) } else { fprintf(fp, " node_online_map: (unused)\n"); } + fprintf(fp, " zero_paddr: %lx\n", vt->zero_paddr); + fprintf(fp, " huge_zero_paddr: %lx\n", vt->huge_zero_paddr); fprintf(fp, " nr_vm_stat_items: %d\n", vt->nr_vm_stat_items); fprintf(fp, " vm_stat_items: %s", (vt->flags & VM_STAT) ? "\n" : "(not used)\n"); diff --git a/x86_64.c b/x86_64.c index 5019c69e452e..693a08bea758 100644 --- a/x86_64.c +++ b/x86_64.c @@ -2114,8 +2114,9 @@ x86_64_uvtop_level4(struct task_context *tc, ulong uvaddr, physaddr_t *paddr, in goto no_upage; if (pmd_pte & _PAGE_PSE) { if (verbose) { - fprintf(fp, " PAGE: %lx (2MB)\n\n", - PAGEBASE(pmd_pte) & PHYSICAL_PAGE_MASK); + fprintf(fp, " PAGE: %lx (2MB%s)\n\n", + PAGEBASE(pmd_pte) & PHYSICAL_PAGE_MASK, + IS_ZEROPAGE(PAGEBASE(pmd_pte) & PHYSICAL_PAGE_MASK) ? ", ZERO PAGE" : ""); x86_64_translate_pte(pmd_pte, 0, 0); } @@ -2143,8 +2144,8 @@ x86_64_uvtop_level4(struct task_context *tc, ulong uvaddr, physaddr_t *paddr, in *paddr = (PAGEBASE(pte) & PHYSICAL_PAGE_MASK) + PAGEOFFSET(uvaddr); if (verbose) { - fprintf(fp, " PAGE: %lx\n\n", - PAGEBASE(*paddr) & PHYSICAL_PAGE_MASK); + fprintf(fp, " PAGE: %lx %s\n\n", PAGEBASE(*paddr) & PHYSICAL_PAGE_MASK, + IS_ZEROPAGE(PAGEBASE(*paddr) & PHYSICAL_PAGE_MASK) ? "(ZERO PAGE)" : ""); x86_64_translate_pte(pte, 0, 0); } -- 2.37.1