linux-toradex.git/mm/vmalloc.c, branch v3.14.3

Revert "mm/vmalloc: interchage the implementation of vmalloc_to_{pfn,page}"

2014-01-28T05:02:39+00:00

Revert commit ece86e222db4, which was intended as a small performance
improvement.

Despite the claim that the patch doesn't introduce any functional
changes in fact it does.

The "no page" path behaves different now.  Originally, vmalloc_to_page
might return NULL under some conditions, with new implementation it
returns pfn_to_page(0) which is not the same as NULL.

Simple test shows the difference.

test.c

#include 
#include 
#include 
#include 

int __init myi(void)
{
	struct page *p;
	void *v;

	v = vmalloc(PAGE_SIZE);
	/* trigger the "no page" path in vmalloc_to_page*/
	vfree(v);

	p = vmalloc_to_page(v);

	pr_err("expected val = NULL, returned val = %p", p);

	return -EBUSY;
}

void __exit mye(void)
{

}
module_init(myi)
module_exit(mye)

Before interchange:
expected val = NULL, returned val =   (null)

After interchange:
expected val = NULL, returned val = c7ebe000

Signed-off-by: Vladimir Murzin 
Cc: Jianyu Zhan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/vmalloc: interchage the implementation of vmalloc_to_{pfn,page}

2014-01-22T00:19:44+00:00

Currently we are implementing vmalloc_to_pfn() as a wrapper around
vmalloc_to_page(), which is implemented as follow:

 1. walks the page talbes to generates the corresponding pfn,
 2. then converts the pfn to struct page,
 3. returns it.

And vmalloc_to_pfn() re-wraps vmalloc_to_page() to get the pfn.

This seems too circuitous, so this patch reverses the way: implement
vmalloc_to_page() as a wrapper around vmalloc_to_pfn().  This makes
vmalloc_to_pfn() and vmalloc_to_page() slightly more efficient.

No functional change.

Signed-off-by: Jianyu Zhan 
Cc: Vladimir Murzin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: kmemleak: avoid false negatives on vmalloc'ed objects

2013-11-13T03:09:07+00:00

Commit 248ac0e1943a ("mm/vmalloc: remove guard page from between vmap
blocks") had the side effect of making vmap_area.va_end member point to
the next vmap_area.va_start.  This was creating an artificial reference
to vmalloc'ed objects and kmemleak was rarely reporting vmalloc() leaks.

This patch marks the vmap_area containing pointers explicitly and
reduces the min ref_count to 2 as vm_struct still contains a reference
to the vmalloc'ed object.  The kmemleak add_scan_area() function has
been improved to allow a SIZE_MAX argument covering the rest of the
object (for simpler calling sites).

Signed-off-by: Catalin Marinas 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

revert mm/vmalloc.c: emit the failure message before return

2013-11-13T03:09:05+00:00

Don't warn twice in __vmalloc_area_node and __vmalloc_node_range if
__vmalloc_area_node allocation failure.  This patch reverts commit
46c001a2753f ("mm/vmalloc.c: emit the failure message before return").

Signed-off-by: Wanpeng Li 
Reviewed-by: Zhang Yanfei 
Cc: Joonsoo Kim 
Cc: KOSAKI Motohiro 
Cc: Mitsuo Hayasaka 
Cc: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/vmalloc: revert "mm/vmalloc.c: check VM_UNINITIALIZED flag in s_show instead of show_numa_info"

2013-11-13T03:09:05+00:00

The VM_UNINITIALIZED/VM_UNLIST flag introduced by f5252e009d5b ("mm:
avoid null pointer access in vm_struct via /proc/vmallocinfo") is used
to avoid accessing the pages field with unallocated page when
show_numa_info() is called.

This patch moves the check just before show_numa_info in order that some
messages still can be dumped via /proc/vmallocinfo.  This patch reverts
commit d157a55815ff ("mm/vmalloc.c: check VM_UNINITIALIZED flag in
s_show instead of show_numa_info");

Reviewed-by: Zhang Yanfei 
Signed-off-by: Wanpeng Li 
Cc: Mitsuo Hayasaka 
Cc: Joonsoo Kim 
Cc: KOSAKI Motohiro 
Cc: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/vmalloc: fix show vmap_area information race with vmap_area tear down

2013-11-13T03:09:05+00:00

There is a race window between vmap_area tear down and show vmap_area
information.

	A                                                B

remove_vm_area
spin_lock(&vmap_area_lock);
va->vm = NULL;
va->flags &= ~VM_VM_AREA;
spin_unlock(&vmap_area_lock);
						spin_lock(&vmap_area_lock);
						if (va->flags & (VM_LAZY_FREE | VM_LAZY_FREEZING))
							return 0;
						if (!(va->flags & VM_VM_AREA)) {
							seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n",
								(void *)va->va_start, (void *)va->va_end,
								va->va_end - va->va_start);
							return 0;
						}
free_unmap_vmap_area(va);
	flush_cache_vunmap
	free_unmap_vmap_area_noflush
		unmap_vmap_area
		free_vmap_area_noflush
			va->flags |= VM_LAZY_FREE

The assumption !VM_VM_AREA represents vm_map_ram allocation is
introduced by d4033afdf828 ("mm, vmalloc: iterate vmap_area_list,
instead of vmlist, in vmallocinfo()").

However, !VM_VM_AREA also represents vmap_area is being tear down in
race window mentioned above.  This patch fix it by don't dump any
information for !VM_VM_AREA case and also remove (VM_LAZY_FREE |
VM_LAZY_FREEING) check since they are not possible for !VM_VM_AREA case.

Suggested-by: Joonsoo Kim 
Acked-by: KOSAKI Motohiro 
Signed-off-by: Wanpeng Li 
Cc: Mitsuo Hayasaka 
Cc: Zhang Yanfei 
Cc: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/vmalloc: don't set area->caller twice

2013-11-13T03:09:05+00:00

The caller address has already been set in set_vmalloc_vm(), there's no
need to set it again in __vmalloc_area_node.

Reviewed-by: Zhang Yanfei 
Signed-off-by: Wanpeng Li 
Cc: Joonsoo Kim 
Cc: KOSAKI Motohiro 
Cc: Mitsuo Hayasaka 
Cc: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/vmalloc: use NUMA_NO_NODE

2013-11-13T03:09:02+00:00

Use more appropriate "if (node == NUMA_NO_NODE)" instead of "if (node < 0)"

Signed-off-by: Jianguo Wu 
Acked-by: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/vmalloc: use wrapper function get_vm_area_size to caculate size of vm area

2013-09-11T22:58:02+00:00

Use wrapper function get_vm_area_size to calculate size of vm area.

Signed-off-by: Wanpeng Li 
Cc: Dave Hansen 
Cc: Rik van Riel 
Cc: Fengguang Wu 
Cc: Joonsoo Kim 
Cc: Johannes Weiner 
Cc: Tejun Heo 
Cc: Yasuaki Ishimatsu 
Cc: David Rientjes 
Cc: KOSAKI Motohiro 
Cc: Jiri Kosina 
Cc: Wanpeng Li 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm, vmalloc: use well-defined find_last_bit() func

2013-09-11T22:57:34+00:00

Our intention in here is to find last_bit within the region to flush.
There is well-defined function, find_last_bit() for this purpose and its
performance may be slightly better than current implementation.  So change
it.

Signed-off-by: Joonsoo Kim 
Reviewed-by: Wanpeng Li 
Acked-by: Johannes Weiner 
Acked-by: Zhang Yanfei 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds