2005-12-20 08:54:35

by Yasunori Goto

[permalink] [raw]
Subject: [Patch] New zone ZONE_EASY_RECLAIM take 4. (disable gfp_easy_reclaim bit)[5/8]

This patch is to disable __GFP_EASY_RECLAIM at some part.
The parts are followings.

1) add_to_page_cache()
2) pipe_writev()
3) shmem_dir_alloc()
4) page_symlink()


1) If this patch is not applied, cache_grow() checks and call BUG(),
at here.

if (flags & ~(SLAB_DMA|SLAB_LEVEL_MASK|SLAB_NO_GROW))
BUG();

This patch is to solve it.

2) This page is allocated by alloc_pages(GFP_HIGHUSER) directly, and
it is kmapped when it is accessed as inode.
But, it is not reclaimed by anyone.

3) This page is used for directory for shmem. So, it is very hard
to reclaim.

4) Same with 2).


take3 -> take 4:
Add disable part to pipe, shmem, and symlink.

Signed-off-by: Yasunori Goto <[email protected]>

Index: zone_reclaim/mm/filemap.c
===================================================================
--- zone_reclaim.orig/mm/filemap.c 2005-12-16 18:36:20.000000000 +0900
+++ zone_reclaim/mm/filemap.c 2005-12-16 19:15:35.000000000 +0900
@@ -395,7 +395,7 @@ int filemap_write_and_wait_range(struct
int add_to_page_cache(struct page *page, struct address_space *mapping,
pgoff_t offset, gfp_t gfp_mask)
{
- int error = radix_tree_preload(gfp_mask & ~__GFP_HIGHMEM);
+ int error = radix_tree_preload(gfp_mask & ~(__GFP_HIGHMEM | __GFP_EASY_RECLAIM));

if (error == 0) {
write_lock_irq(&mapping->tree_lock);
Index: zone_reclaim/fs/pipe.c
===================================================================
--- zone_reclaim.orig/fs/pipe.c 2005-12-16 18:36:20.000000000 +0900
+++ zone_reclaim/fs/pipe.c 2005-12-16 19:15:35.000000000 +0900
@@ -284,7 +284,7 @@ pipe_writev(struct file *filp, const str
int error;

if (!page) {
- page = alloc_page(GFP_HIGHUSER);
+ page = alloc_page(GFP_HIGHUSER & ~__GFP_EASY_RECLAIM);
if (unlikely(!page)) {
ret = ret ? : -ENOMEM;
break;
Index: zone_reclaim/mm/shmem.c
===================================================================
--- zone_reclaim.orig/mm/shmem.c 2005-12-16 18:36:20.000000000 +0900
+++ zone_reclaim/mm/shmem.c 2005-12-16 19:15:35.000000000 +0900
@@ -89,6 +89,7 @@ static inline struct page *shmem_dir_all
* BLOCKS_PER_PAGE on indirect pages, assume PAGE_CACHE_SIZE:
* might be reconsidered if it ever diverges from PAGE_SIZE.
*/
+ gfp_mask &= ~__GFP_EASY_RECLAIM;
return alloc_pages(gfp_mask, PAGE_CACHE_SHIFT-PAGE_SHIFT);
}

Index: zone_reclaim/fs/namei.c
===================================================================
--- zone_reclaim.orig/fs/namei.c 2005-12-16 18:36:20.000000000 +0900
+++ zone_reclaim/fs/namei.c 2005-12-16 19:30:49.000000000 +0900
@@ -2502,10 +2502,12 @@ void page_put_link(struct dentry *dentry
int page_symlink(struct inode *inode, const char *symname, int len)
{
struct address_space *mapping = inode->i_mapping;
- struct page *page = grab_cache_page(mapping, 0);
+ struct page *page;
int err = -ENOMEM;
char *kaddr;

+ mapping_set_gfp_mask(mapping, mapping_gfp_mask(mapping) & ~__GFP_EASY_RECLAIM);
+ page = grab_cache_page(mapping, 0);
if (!page)
goto fail;
err = mapping->a_ops->prepare_write(NULL, page, 0, len-1);

--
Yasunori Goto



2006-01-03 21:34:29

by Joel Schopp

[permalink] [raw]
Subject: Re: [Patch] New zone ZONE_EASY_RECLAIM take 4. (disable gfp_easy_reclaim bit)[5/8]


> ===================================================================
> --- zone_reclaim.orig/fs/pipe.c 2005-12-16 18:36:20.000000000 +0900
> +++ zone_reclaim/fs/pipe.c 2005-12-16 19:15:35.000000000 +0900
> @@ -284,7 +284,7 @@ pipe_writev(struct file *filp, const str
> int error;
>
> if (!page) {
> - page = alloc_page(GFP_HIGHUSER);
> + page = alloc_page(GFP_HIGHUSER & ~__GFP_EASY_RECLAIM);
> if (unlikely(!page)) {
> ret = ret ? : -ENOMEM;
> break;

That is a bit hard to understand. How about a new GFP_HIGHUSER_HARD or
somesuch define back in patch 1, then use it here?


2006-01-05 05:44:12

by Yasunori Goto

[permalink] [raw]
Subject: Re: [Patch] New zone ZONE_EASY_RECLAIM take 4. (disable gfp_easy_reclaim bit)[5/8]

>
> > ===================================================================
> > --- zone_reclaim.orig/fs/pipe.c 2005-12-16 18:36:20.000000000 +0900
> > +++ zone_reclaim/fs/pipe.c 2005-12-16 19:15:35.000000000 +0900
> > @@ -284,7 +284,7 @@ pipe_writev(struct file *filp, const str
> > int error;
> >
> > if (!page) {
> > - page = alloc_page(GFP_HIGHUSER);
> > + page = alloc_page(GFP_HIGHUSER & ~__GFP_EASY_RECLAIM);
> > if (unlikely(!page)) {
> > ret = ret ? : -ENOMEM;
> > break;
>
> That is a bit hard to understand. How about a new GFP_HIGHUSER_HARD or
> somesuch define back in patch 1, then use it here?

It looks better. Thanks for your idea.

--
Yasunori Goto


2006-01-05 09:47:47

by Mel Gorman

[permalink] [raw]
Subject: Re: [Patch] New zone ZONE_EASY_RECLAIM take 4. (disable gfp_easy_reclaim bit)[5/8]

On (05/01/06 14:43), Yasunori Goto didst pronounce:
> >
> > > ===================================================================
> > > --- zone_reclaim.orig/fs/pipe.c 2005-12-16 18:36:20.000000000 +0900
> > > +++ zone_reclaim/fs/pipe.c 2005-12-16 19:15:35.000000000 +0900
> > > @@ -284,7 +284,7 @@ pipe_writev(struct file *filp, const str
> > > int error;
> > >
> > > if (!page) {
> > > - page = alloc_page(GFP_HIGHUSER);
> > > + page = alloc_page(GFP_HIGHUSER & ~__GFP_EASY_RECLAIM);
> > > if (unlikely(!page)) {
> > > ret = ret ? : -ENOMEM;
> > > break;
> >
> > That is a bit hard to understand. How about a new GFP_HIGHUSER_HARD or
> > somesuch define back in patch 1, then use it here?
>
> It looks better. Thanks for your idea.
>

There are other places where GFP_HIGHUSER is used for pages that are not easily
reclaimed. It is easier clearer to add __GFP_EASY_RECLAIM at the places you
know pages are easily reclaimed rather than removing __GFP_EASY_RECLAIM from
awkward places.

--
Mel Gorman
Part-time Phd Student
University of Limerick IBM Dublin Software Lab

2006-01-05 11:00:41

by Yasunori Goto

[permalink] [raw]
Subject: Re: [Patch] New zone ZONE_EASY_RECLAIM take 4. (disable gfp_easy_reclaim bit)[5/8]

> On (05/01/06 14:43), Yasunori Goto didst pronounce:
> > >
> > > > ===================================================================
> > > > --- zone_reclaim.orig/fs/pipe.c 2005-12-16 18:36:20.000000000 +0900
> > > > +++ zone_reclaim/fs/pipe.c 2005-12-16 19:15:35.000000000 +0900
> > > > @@ -284,7 +284,7 @@ pipe_writev(struct file *filp, const str
> > > > int error;
> > > >
> > > > if (!page) {
> > > > - page = alloc_page(GFP_HIGHUSER);
> > > > + page = alloc_page(GFP_HIGHUSER & ~__GFP_EASY_RECLAIM);
> > > > if (unlikely(!page)) {
> > > > ret = ret ? : -ENOMEM;
> > > > break;
> > >
> > > That is a bit hard to understand. How about a new GFP_HIGHUSER_HARD or
> > > somesuch define back in patch 1, then use it here?
> >
> > It looks better. Thanks for your idea.
> >
>
> There are other places where GFP_HIGHUSER is used for pages that are not easily
> reclaimed. It is easier clearer to add __GFP_EASY_RECLAIM at the places you
> know pages are easily reclaimed rather than removing __GFP_EASY_RECLAIM from
> awkward places.

I thought that other pages can be migrated by Chlistoph-san's (and
Kame-san's) patch. May I ask which page should be no EASY_RECLAIM?
Am I overlooking anything?


Thanks.

--
Yasunori Goto


2006-01-05 11:23:31

by Mel Gorman

[permalink] [raw]
Subject: Re: [Patch] New zone ZONE_EASY_RECLAIM take 4. (disable gfp_easy_reclaim bit)[5/8]

On (05/01/06 19:59), Yasunori Goto didst pronounce:
> > On (05/01/06 14:43), Yasunori Goto didst pronounce:
> > > >
> > > > > ===================================================================
> > > > > --- zone_reclaim.orig/fs/pipe.c 2005-12-16 18:36:20.000000000 +0900
> > > > > +++ zone_reclaim/fs/pipe.c 2005-12-16 19:15:35.000000000 +0900
> > > > > @@ -284,7 +284,7 @@ pipe_writev(struct file *filp, const str
> > > > > int error;
> > > > >
> > > > > if (!page) {
> > > > > - page = alloc_page(GFP_HIGHUSER);
> > > > > + page = alloc_page(GFP_HIGHUSER & ~__GFP_EASY_RECLAIM);
> > > > > if (unlikely(!page)) {
> > > > > ret = ret ? : -ENOMEM;
> > > > > break;
> > > >
> > > > That is a bit hard to understand. How about a new GFP_HIGHUSER_HARD or
> > > > somesuch define back in patch 1, then use it here?
> > >
> > > It looks better. Thanks for your idea.
> > >
> >
> > There are other places where GFP_HIGHUSER is used for pages that are not easily
> > reclaimed. It is easier clearer to add __GFP_EASY_RECLAIM at the places you
> > know pages are easily reclaimed rather than removing __GFP_EASY_RECLAIM from
> > awkward places.
>
> I thought that other pages can be migrated by Chlistoph-san's (and
> Kame-san's) patch.

Then the pages are not "easily reclaimed", they can just be moved by
some other mechanism.

> May I ask which page should be no EASY_RECLAIM?

Based on http://lxr.linux.no/ident?i=GFP_HIGHUSER, examples include HugeTLB
pages, pages allocated by the infiniband driver, pages allocated by the NFS
driver and inode pages.

--
Mel Gorman
Part-time Phd Student Linux Technology Center
University of Limerick IBM Dublin Software Lab

2006-01-06 01:37:29

by Yasunori Goto

[permalink] [raw]
Subject: Re: [Lhms-devel] Re: [Patch] New zone ZONE_EASY_RECLAIM take 4. (disable gfp_easy_reclaim bit)[5/8]

> On (05/01/06 19:59), Yasunori Goto didst pronounce:
> > > On (05/01/06 14:43), Yasunori Goto didst pronounce:
> > > > >
> > > > > > ===================================================================
> > > > > > --- zone_reclaim.orig/fs/pipe.c 2005-12-16 18:36:20.000000000 +0900
> > > > > > +++ zone_reclaim/fs/pipe.c 2005-12-16 19:15:35.000000000 +0900
> > > > > > @@ -284,7 +284,7 @@ pipe_writev(struct file *filp, const str
> > > > > > int error;
> > > > > >
> > > > > > if (!page) {
> > > > > > - page = alloc_page(GFP_HIGHUSER);
> > > > > > + page = alloc_page(GFP_HIGHUSER & ~__GFP_EASY_RECLAIM);
> > > > > > if (unlikely(!page)) {
> > > > > > ret = ret ? : -ENOMEM;
> > > > > > break;
> > > > >
> > > > > That is a bit hard to understand. How about a new GFP_HIGHUSER_HARD or
> > > > > somesuch define back in patch 1, then use it here?
> > > >
> > > > It looks better. Thanks for your idea.
> > > >
> > >
> > > There are other places where GFP_HIGHUSER is used for pages that are not easily
> > > reclaimed. It is easier clearer to add __GFP_EASY_RECLAIM at the places you
> > > know pages are easily reclaimed rather than removing __GFP_EASY_RECLAIM from
> > > awkward places.
> >
> > I thought that other pages can be migrated by Chlistoph-san's (and
> > Kame-san's) patch.
>
> Then the pages are not "easily reclaimed", they can just be moved by
> some other mechanism.

Ah. My naming was no good. :-(


> > May I ask which page should be no EASY_RECLAIM?
>
> Based on http://lxr.linux.no/ident?i=GFP_HIGHUSER, examples include HugeTLB
> pages, pages allocated by the infiniband driver, pages allocated by the NFS
> driver and inode pages.

Hmmmm.
Ok. Your proposal looks better.

Thanks.

--
Yasunori Goto