The patch titled
x86: use clear_page(), copy_page() and __GFP_ZERO in favor of memset()/memcpy() on whole pages
has been added to the -mm tree. Its filename is
x86-use-clear_page-copy_page-and-__gfp_zero-in-favor-of-memset-memcpy-on-whole-pages.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: x86: use clear_page(), copy_page() and __GFP_ZERO in favor of memset()/memcpy() on whole pages
From: "Jan Beulich" <JBeulich@xxxxxxxxxx>
After all that's what they are intended for.
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/machine_kexec_64.c | 4 ++--
arch/x86/kvm/lapic.c | 3 +--
arch/x86/mm/init_32.c | 4 ++--
arch/x86/mm/init_64.c | 2 +-
4 files changed, 6 insertions(+), 7 deletions(-)
diff -puN arch/x86/kernel/machine_kexec_64.c~x86-use-clear_page-copy_page-and-__gfp_zero-in-favor-of-memset-memcpy-on-whole-pages arch/x86/kernel/machine_kexec_64.c
--- a/arch/x86/kernel/machine_kexec_64.c~x86-use-clear_page-copy_page-and-__gfp_zero-in-favor-of-memset-memcpy-on-whole-pages
+++ a/arch/x86/kernel/machine_kexec_64.c
@@ -36,7 +36,7 @@ static int init_one_level2_page(struct k
if (!page)
goto out;
pud = (pud_t *)page_address(page);
- memset(pud, 0, PAGE_SIZE);
+ clear_page(pud);
set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE));
}
pud = pud_offset(pgd, addr);
@@ -45,7 +45,7 @@ static int init_one_level2_page(struct k
if (!page)
goto out;
pmd = (pmd_t *)page_address(page);
- memset(pmd, 0, PAGE_SIZE);
+ clear_page(pmd);
set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));
}
pmd = pmd_offset(pud, addr);
diff -puN arch/x86/kvm/lapic.c~x86-use-clear_page-copy_page-and-__gfp_zero-in-favor-of-memset-memcpy-on-whole-pages arch/x86/kvm/lapic.c
--- a/arch/x86/kvm/lapic.c~x86-use-clear_page-copy_page-and-__gfp_zero-in-favor-of-memset-memcpy-on-whole-pages
+++ a/arch/x86/kvm/lapic.c
@@ -1056,14 +1056,13 @@ int kvm_create_lapic(struct kvm_vcpu *vc
vcpu->arch.apic = apic;
- apic->regs_page = alloc_page(GFP_KERNEL);
+ apic->regs_page = alloc_page(GFP_KERNEL|__GFP_ZERO);
if (apic->regs_page == NULL) {
printk(KERN_ERR "malloc apic regs error for vcpu %x\n",
vcpu->vcpu_id);
goto nomem_free_apic;
}
apic->regs = page_address(apic->regs_page);
- memset(apic->regs, 0, PAGE_SIZE);
apic->vcpu = vcpu;
hrtimer_init(&apic->lapic_timer.timer, CLOCK_MONOTONIC,
diff -puN arch/x86/mm/init_32.c~x86-use-clear_page-copy_page-and-__gfp_zero-in-favor-of-memset-memcpy-on-whole-pages arch/x86/mm/init_32.c
--- a/arch/x86/mm/init_32.c~x86-use-clear_page-copy_page-and-__gfp_zero-in-favor-of-memset-memcpy-on-whole-pages
+++ a/arch/x86/mm/init_32.c
@@ -67,7 +67,7 @@ static __init void *alloc_low_page(void)
panic("alloc_low_page: ran out of memory");
adr = __va(pfn * PAGE_SIZE);
- memset(adr, 0, PAGE_SIZE);
+ clear_page(adr);
return adr;
}
@@ -558,7 +558,7 @@ char swsusp_pg_dir[PAGE_SIZE]
static inline void save_pg_dir(void)
{
- memcpy(swsusp_pg_dir, swapper_pg_dir, PAGE_SIZE);
+ copy_page(swsusp_pg_dir, swapper_pg_dir);
}
#else /* !CONFIG_ACPI_SLEEP */
static inline void save_pg_dir(void)
diff -puN arch/x86/mm/init_64.c~x86-use-clear_page-copy_page-and-__gfp_zero-in-favor-of-memset-memcpy-on-whole-pages arch/x86/mm/init_64.c
--- a/arch/x86/mm/init_64.c~x86-use-clear_page-copy_page-and-__gfp_zero-in-favor-of-memset-memcpy-on-whole-pages
+++ a/arch/x86/mm/init_64.c
@@ -323,7 +323,7 @@ static __ref void *alloc_low_page(unsign
panic("alloc_low_page: ran out of memory");
adr = early_memremap(pfn * PAGE_SIZE, PAGE_SIZE);
- memset(adr, 0, PAGE_SIZE);
+ clear_page(adr);
*phys = pfn * PAGE_SIZE;
return adr;
}
_
Patches currently in -mm which might be from JBeulich@xxxxxxxxxx are
linux-next.patch
x86-use-clear_page-copy_page-and-__gfp_zero-in-favor-of-memset-memcpy-on-whole-pages.patch
modules-no-need-to-align-modinfo-strings.patch
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