lkml.org 
[lkml]   [2019]   [Jun]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH RESEND 4/8] x86, hugetlbpage: Start fallback of top-down mmap at mm->mmap_base
Date
In case of mmap failure in top-down mode, there is no need to go through
the whole address space again for the bottom-up fallback: the goal of this
fallback is to find, as a last resort, space between the top-down mmap base
and the stack, which is the only place not covered by the top-down mmap.

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
---
arch/x86/mm/hugetlbpage.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c
index fab095362c50..4b90339aef50 100644
--- a/arch/x86/mm/hugetlbpage.c
+++ b/arch/x86/mm/hugetlbpage.c
@@ -106,11 +106,12 @@ static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
{
struct hstate *h = hstate_file(file);
struct vm_unmapped_area_info info;
+ unsigned long mmap_base = get_mmap_base(0);

info.flags = VM_UNMAPPED_AREA_TOPDOWN;
info.length = len;
info.low_limit = PAGE_SIZE;
- info.high_limit = get_mmap_base(0);
+ info.high_limit = mmap_base;

/*
* If hint address is above DEFAULT_MAP_WINDOW, look for unmapped area
@@ -132,7 +133,7 @@ static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
if (addr & ~PAGE_MASK) {
VM_BUG_ON(addr != -ENOMEM);
info.flags = 0;
- info.low_limit = TASK_UNMAPPED_BASE;
+ info.low_limit = mmap_base;
info.high_limit = TASK_SIZE_LOW;
addr = vm_unmapped_area(&info);
}
--
2.20.1
\
 
 \ /
  Last update: 2019-06-20 08:03    [W:0.126 / U:7.216 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site