lkml.org 
[lkml]   [2013]   [Aug]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 5/8] mm: make clear_huge_page cache clear only around the fault address
Date
---
mm/memory.c | 28 ++++++++++++++++++++++++++--
1 file changed, 26 insertions(+), 2 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index 69a5a38..17d61f0 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4231,18 +4231,35 @@ 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)
{
int i;
struct page *p = page;
+ unsigned long vaddr;
+ unsigned long haddr = addr & HPAGE_PMD_MASK;
+ int target = (addr - haddr) >> PAGE_SHIFT;

might_sleep();
+ vaddr = haddr;
for (i = 0; i < pages_per_huge_page;
i++, p = mem_map_next(p, page, i)) {
cond_resched();
- clear_user_highpage(p, addr + i * PAGE_SIZE);
+ vaddr = haddr + 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,
@@ -4250,6 +4267,8 @@ void clear_huge_page(struct page *page,
{
int i;
unsigned long haddr = addr & HPAGE_PMD_MASK;
+ unsigned long vaddr;
+ int target = (addr - haddr) >> PAGE_SHIFT;

if (unlikely(pages_per_huge_page > MAX_ORDER_NR_PAGES)) {
clear_gigantic_page(page, haddr, pages_per_huge_page);
@@ -4257,9 +4276,14 @@ void clear_huge_page(struct page *page,
}

might_sleep();
+ vaddr = haddr;
for (i = 0; i < pages_per_huge_page; i++) {
cond_resched();
- clear_user_highpage(page + i, haddr + i * PAGE_SIZE);
+ vaddr = haddr + i*PAGE_SIZE;
+ if (!ARCH_HAS_USER_NOCACHE || i == target)
+ clear_user_highpage(page + i, vaddr);
+ else
+ clear_user_highpage_nocache(page + i, vaddr);
}
}

--
1.7.12.4


\
 
 \ /
  Last update: 2013-08-16 17:01    [W:0.116 / U:2.708 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site