From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
To: linux-mm@kvack.org
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, Andi Kleen <ak@linux.intel.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Tim Chen <tim.c.chen@linux.intel.com>,
Alex Shi <alex.shu@intel.com>, Jan Beulich <jbeulich@novell.com>,
Robert Richter <robert.richter@amd.com>,
Andy Lutomirski <luto@amacapital.net>,
Andrew Morton <akpm@linux-foundation.org>,
Andrea Arcangeli <aarcange@redhat.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Hugh Dickins <hughd@google.com>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Mel Gorman <mgorman@suse.de>,
linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
linux-mips@linux-mips.org, linux-sh@vger.kernel.org,
sparclinux@vger.kernel.org
Subject: [PATCH v4 6/8] mm: make clear_huge_page cache clear only around the fault address
Date: Mon, 20 Aug 2012 16:52:35 +0300 [thread overview]
Message-ID: <1345470757-12005-7-git-send-email-kirill.shutemov@linux.intel.com> (raw)
In-Reply-To: <1345470757-12005-1-git-send-email-kirill.shutemov@linux.intel.com>
From: Andi Kleen <ak@linux.intel.com>
Clearing a 2MB huge page will typically blow away several levels
of CPU caches. To avoid this only cache clear the 4K area
around the fault address and use a cache avoiding clears
for the rest of the 2MB area.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
mm/memory.c | 37 +++++++++++++++++++++++++++++--------
1 files changed, 29 insertions(+), 8 deletions(-)
diff --git a/mm/memory.c b/mm/memory.c
index dfc179b..625ca33 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3969,18 +3969,32 @@ EXPORT_SYMBOL(might_fault);
#endif
#if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLBFS)
+
+#ifndef ARCH_HAS_USER_NOCACHE
+#define ARCH_HAS_USER_NOCACHE 0
+#endif
+
+#if ARCH_HAS_USER_NOCACHE == 0
+#define clear_user_highpage_nocache clear_user_highpage
+#endif
+
static void clear_gigantic_page(struct page *page,
- unsigned long addr,
- unsigned int pages_per_huge_page)
+ unsigned long haddr, unsigned long fault_address,
+ unsigned int pages_per_huge_page)
{
int i;
struct page *p = page;
+ unsigned long vaddr;
+ int target = (fault_address - haddr) >> PAGE_SHIFT;
might_sleep();
- for (i = 0; i < pages_per_huge_page;
- i++, p = mem_map_next(p, page, i)) {
+ for (i = 0, vaddr = haddr; i < pages_per_huge_page;
+ i++, p = mem_map_next(p, page, i), vaddr += PAGE_SIZE) {
cond_resched();
- clear_user_highpage(p, addr + i * PAGE_SIZE);
+ if (!ARCH_HAS_USER_NOCACHE || i == target)
+ clear_user_highpage(p, vaddr);
+ else
+ clear_user_highpage_nocache(p, vaddr);
}
}
void clear_huge_page(struct page *page,
@@ -3988,16 +4002,23 @@ void clear_huge_page(struct page *page,
unsigned int pages_per_huge_page)
{
int i;
+ unsigned long vaddr;
+ int target = (fault_address - haddr) >> PAGE_SHIFT;
if (unlikely(pages_per_huge_page > MAX_ORDER_NR_PAGES)) {
- clear_gigantic_page(page, haddr, pages_per_huge_page);
+ clear_gigantic_page(page, haddr, fault_address,
+ pages_per_huge_page);
return;
}
might_sleep();
- for (i = 0; i < pages_per_huge_page; i++) {
+ for (i = 0, vaddr = haddr; i < pages_per_huge_page;
+ i++, page++, vaddr += PAGE_SIZE) {
cond_resched();
- clear_user_highpage(page + i, haddr + i * PAGE_SIZE);
+ if (!ARCH_HAS_USER_NOCACHE || i == target)
+ clear_user_highpage(page, vaddr);
+ else
+ clear_user_highpage_nocache(page, vaddr);
}
}
--
1.7.7.6
next prev parent reply other threads:[~2012-08-20 13:54 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-20 13:52 [PATCH v4 0/8] Avoid cache trashing on clearing huge/gigantic page Kirill A. Shutemov
2012-08-20 13:52 ` [PATCH v4 1/8] THP: Use real address for NUMA policy Kirill A. Shutemov
2012-08-20 13:52 ` [PATCH v4 2/8] THP: Pass fault address to __do_huge_pmd_anonymous_page() Kirill A. Shutemov
2012-08-20 13:52 ` [PATCH v4 3/8] hugetlb: pass fault address to hugetlb_no_page() Kirill A. Shutemov
2012-08-20 13:52 ` [PATCH v4 4/8] mm: pass fault address to clear_huge_page() Kirill A. Shutemov
2012-08-20 13:52 ` [PATCH v4 5/8] x86: Add clear_page_nocache Kirill A. Shutemov
2012-08-20 13:52 ` Kirill A. Shutemov [this message]
2012-08-20 13:52 ` [PATCH v4 7/8] x86: switch the 64bit uncached page clear to SSE/AVX v2 Kirill A. Shutemov
2012-08-20 13:52 ` [PATCH v4 8/8] mm: implement vm.clear_huge_page_nocache sysctl Kirill A. Shutemov
2012-09-12 10:09 ` [PATCH v4 0/8] Avoid cache trashing on clearing huge/gigantic page Kirill A. Shutemov
2012-09-13 23:05 ` Andrew Morton
2012-09-14 5:52 ` Ingo Molnar
2012-09-25 14:27 ` Kirill A. Shutemov
2012-09-25 19:33 ` Andrea Arcangeli
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