[PATCH] [8/8] CPA: Add statistics about state of direct mapping

Andi Kleen
2008-02-11T09:52:45Z

Add information about the mapping state of the direct mapping to /proc/meminfo.

This way we can see how many large pages are really used for it.

Signed-off-by: Andi Kleen <ak@suse.de>

---
arch/x86/mm/init_32.c | 2 ++
arch/x86/mm/init_64.c | 2 ++
arch/x86/mm/pageattr.c | 21 +++++++++++++++++++++
fs/proc/proc_misc.c | 7 +++++++
include/asm-x86/pgtable.h | 3 +++
5 files changed, 35 insertions(+)

Index: linux/arch/x86/mm/init_64.c
===================================================================
--- linux.orig/arch/x86/mm/init_64.c
+++ linux/arch/x86/mm/init_64.c
@@ -306,6 +306,7 @@ phys_pmd_init(pmd_t *pmd_page, unsigned
if (pmd_val(*pmd))
continue;

+ dpages_cnt[PG_LEVEL_2M]++;
set_pte((pte_t *)pmd,
pfn_pte(address >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
}
@@ -351,6 +352,7 @@ phys_pud_init(pud_t *pud_page, unsigned
}

if (direct_gbpages) {
+ dpages_cnt[PG_LEVEL_1G]++;
set_pte((pte_t *)pud,
pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
true_end = (addr & PUD_MASK) + PUD_SIZE;
Index: linux/arch/x86/mm/pageattr.c
===================================================================
--- linux.orig/arch/x86/mm/pageattr.c
+++ linux/arch/x86/mm/pageattr.c
@@ -18,6 +18,8 @@
#include <asm/uaccess.h>
#include <asm/pgalloc.h>

+unsigned long dpages_cnt[PG_LEVEL_NUM];
+
/*
* The current flushing context - we pass it instead of 5 arguments:
*/
@@ -516,6 +518,11 @@ static int split_large_page(pte_t *kpte,
for (i = 0; i < PTRS_PER_PTE; i++, pfn += pfninc)
set_pte(&pbase[i], pfn_pte(pfn, ref_prot));

+ if (address >= __va(0) && address < __va(end_pfn_map)) {
+ dpages_cnt[level]--;
+ dpages_cnt[level - 1] += PTRS_PER_PTE;
+ }
+
/*
* Install the new, split up pagetable. Important details here:
*
@@ -961,6 +968,22 @@ __initcall(debug_pagealloc_proc_init);

#endif

+#ifdef CONFIG_PROC_FS
+int arch_report_meminfo(char *page)
+{
+ int n;
+ n = sprintf(page, "DirectMap4k: %8lu\n"
+ "DirectMap2M: %8lu\n",
+ dpages_cnt[PG_LEVEL_4K],
+ dpages_cnt[PG_LEVEL_2M]);
+#ifdef CONFIG_X86_64
+ n += sprintf(page + n, "DirectMap1G: %8lu\n",
+ dpages_cnt[PG_LEVEL_1G]);
+#endif
+ return n;
+}
+#endif
+
/*
* The testcases use internal knowledge of the implementation that shouldn't
* be exposed to the rest of the kernel. Include these directly here.
Index: linux/include/asm-x86/pgtable.h
===================================================================
--- linux.orig/include/asm-x86/pgtable.h
+++ linux/include/asm-x86/pgtable.h
@@ -247,8 +247,11 @@ enum {
PG_LEVEL_4K,
PG_LEVEL_2M,
PG_LEVEL_1G,
+ PG_LEVEL_NUM
};

+extern unsigned long dpages_cnt[PG_LEVEL_NUM];
+
/*
* Helper function that returns the kernel pagetable entry controlling
* the virtual address 'address'. NULL means no pagetable entry present.
Index: linux/arch/x86/mm/init_32.c
===================================================================
--- linux.orig/arch/x86/mm/init_32.c
+++ linux/arch/x86/mm/init_32.c
@@ -192,6 +192,7 @@ static void __init kernel_physical_mappi
is_kernel_text(addr2))
prot = PAGE_KERNEL_LARGE_EXEC;

+ dpages_cnt[PG_LEVEL_2M]++;
set_pmd(pmd, pfn_pmd(pfn, prot));

pfn += PTRS_PER_PTE;
@@ -208,6 +209,7 @@ static void __init kernel_physical_mappi
if (is_kernel_text(addr))
prot = PAGE_KERNEL_EXEC;

+ dpages_cnt[PG_LEVEL_4K]++;
set_pte(pte, pfn_pte(pfn, prot));
}
end_pfn_map = pfn;
Index: linux/fs/proc/proc_misc.c
===================================================================
--- linux.orig/fs/proc/proc_misc.c
+++ linux/fs/proc/proc_misc.c
@@ -122,6 +122,11 @@ static int uptime_read_proc(char *page,
return proc_calc_metrics(page, start, off, count, eof, len);
}

+int __attribute__((weak)) arch_report_meminfo(char *page)
+{
+ return 0;
+}
+
static int meminfo_read_proc(char *page, char **start, off_t off,
int count, int *eof, void *data)
{
@@ -218,6 +223,8 @@ static int meminfo_read_proc(char *page,

len += hugetlb_report_meminfo(page + len);

+ len += arch_report_meminfo(page + len);
+
return proc_calc_metrics(page, start, off, count, eof, len);
#undef K
}