From: Joel Schopp <jschopp@austin.ibm.com>
To: Paul Jackson <pj@sgi.com>
Cc: haveblue@us.ibm.com, mrmacman_g4@mac.com, akpm@osdl.org,
lhms-devel@lists.sourceforge.net, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, mel@csn.ul.ie, kravetz@us.ibm.com
Subject: Re: [Lhms-devel] Re: [PATCH 1/9] add defrag flags
Date: Tue, 27 Sep 2005 17:03:50 -0500 [thread overview]
Message-ID: <4339C1C6.8040202@austin.ibm.com> (raw)
In-Reply-To: <20050927142355.232f6e95.pj@sgi.com>
[-- Attachment #1: Type: text/plain, Size: 822 bytes --]
> Well, then, at least fix the comment, from the rather oddly phrased:
>
> #define __GFP_USER 0x40000u /* User is a userspace user */
>
> to something more accurate such as:
>
> #define __GFP_USER 0x40000u /* User and other really easily reclaimed pages */
This was a cleverly designed trick to push me over the 80 column per line limit.
I've seen through your ruse and added:
#define __GFP_USER 0x40000u /* User & other really easily reclaimed pages */
>
> And consider adding a comment to its use in fs/buffer.c, where marking
> a page obviously destined for kernel space __GFP_USER seems strange.
> I doubt I will be the last person to look at the line of code and
> scratch my head.
Done. Patch with the two updated comments attached.
I think all hairs have been split and we can merge this one now.
[-- Attachment #2: 1_add_defrag_flags --]
[-- Type: text/plain, Size: 5476 bytes --]
Index: 2.6.13-joel2/fs/buffer.c
===================================================================
--- 2.6.13-joel2.orig/fs/buffer.c 2005-09-13 14:54:13.%N -0500
+++ 2.6.13-joel2/fs/buffer.c 2005-09-27 16:52:05.%N -0500
@@ -1119,7 +1119,12 @@ grow_dev_page(struct block_device *bdev,
struct page *page;
struct buffer_head *bh;
- page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
+ /*
+ * Mark as __GFP_USER because from a fragmentation avoidance and
+ * reclimation point of view this memory behaves like user memory.
+ */
+ page = find_or_create_page(inode->i_mapping, index,
+ GFP_NOFS | __GFP_USER);
if (!page)
return NULL;
@@ -3044,7 +3049,8 @@ static void recalc_bh_state(void)
struct buffer_head *alloc_buffer_head(unsigned int __nocast gfp_flags)
{
- struct buffer_head *ret = kmem_cache_alloc(bh_cachep, gfp_flags);
+ struct buffer_head *ret = kmem_cache_alloc(bh_cachep,
+ gfp_flags|__GFP_KERNRCLM);
if (ret) {
preempt_disable();
__get_cpu_var(bh_accounting).nr++;
Index: 2.6.13-joel2/fs/dcache.c
===================================================================
--- 2.6.13-joel2.orig/fs/dcache.c 2005-09-13 14:54:14.%N -0500
+++ 2.6.13-joel2/fs/dcache.c 2005-09-13 15:02:01.%N -0500
@@ -721,7 +721,7 @@ struct dentry *d_alloc(struct dentry * p
struct dentry *dentry;
char *dname;
- dentry = kmem_cache_alloc(dentry_cache, GFP_KERNEL);
+ dentry = kmem_cache_alloc(dentry_cache, GFP_KERNEL|__GFP_KERNRCLM);
if (!dentry)
return NULL;
Index: 2.6.13-joel2/fs/ext2/super.c
===================================================================
--- 2.6.13-joel2.orig/fs/ext2/super.c 2005-09-13 14:54:14.%N -0500
+++ 2.6.13-joel2/fs/ext2/super.c 2005-09-13 15:02:01.%N -0500
@@ -138,7 +138,8 @@ static kmem_cache_t * ext2_inode_cachep;
static struct inode *ext2_alloc_inode(struct super_block *sb)
{
struct ext2_inode_info *ei;
- ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, SLAB_KERNEL);
+ ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep,
+ SLAB_KERNEL|__GFP_KERNRCLM);
if (!ei)
return NULL;
#ifdef CONFIG_EXT2_FS_POSIX_ACL
Index: 2.6.13-joel2/fs/ext3/super.c
===================================================================
--- 2.6.13-joel2.orig/fs/ext3/super.c 2005-09-13 14:54:14.%N -0500
+++ 2.6.13-joel2/fs/ext3/super.c 2005-09-13 15:02:01.%N -0500
@@ -440,7 +440,7 @@ static struct inode *ext3_alloc_inode(st
{
struct ext3_inode_info *ei;
- ei = kmem_cache_alloc(ext3_inode_cachep, SLAB_NOFS);
+ ei = kmem_cache_alloc(ext3_inode_cachep, SLAB_NOFS|__GFP_KERNRCLM);
if (!ei)
return NULL;
#ifdef CONFIG_EXT3_FS_POSIX_ACL
Index: 2.6.13-joel2/fs/ntfs/inode.c
===================================================================
--- 2.6.13-joel2.orig/fs/ntfs/inode.c 2005-09-13 14:54:14.%N -0500
+++ 2.6.13-joel2/fs/ntfs/inode.c 2005-09-13 15:05:53.%N -0500
@@ -317,7 +317,7 @@ struct inode *ntfs_alloc_big_inode(struc
ntfs_inode *ni;
ntfs_debug("Entering.");
- ni = kmem_cache_alloc(ntfs_big_inode_cache, SLAB_NOFS);
+ ni = kmem_cache_alloc(ntfs_big_inode_cache, SLAB_NOFS|__GFP_KERNRCLM);
if (likely(ni != NULL)) {
ni->state = 0;
return VFS_I(ni);
@@ -342,7 +342,7 @@ static inline ntfs_inode *ntfs_alloc_ext
ntfs_inode *ni;
ntfs_debug("Entering.");
- ni = kmem_cache_alloc(ntfs_inode_cache, SLAB_NOFS);
+ ni = kmem_cache_alloc(ntfs_inode_cache, SLAB_NOFS|__GFP_KERNRCLM);
if (likely(ni != NULL)) {
ni->state = 0;
return ni;
Index: 2.6.13-joel2/include/linux/gfp.h
===================================================================
--- 2.6.13-joel2.orig/include/linux/gfp.h 2005-09-13 14:54:17.%N -0500
+++ 2.6.13-joel2/include/linux/gfp.h 2005-09-27 16:40:55.%N -0500
@@ -41,6 +41,16 @@ struct vm_area_struct;
#define __GFP_NOMEMALLOC 0x10000u /* Don't use emergency reserves */
#define __GFP_NORECLAIM 0x20000u /* No realy zone reclaim during allocation */
+/* Allocation type modifiers, these are required to be adjacent
+ * __GPF_USER: Allocation for user page or a buffer page
+ * __GFP_KERNRCLM: Short-lived or reclaimable kernel allocation
+ * Both bits off: Kernel non-reclaimable or very hard to reclaim
+ * RCLM_SHIFT (defined elsewhere) depends on the location of these bits
+ */
+#define __GFP_USER 0x40000u /* User & other really easily reclaimed pages */
+#define __GFP_KERNRCLM 0x80000u /* Kernel page that is easily reclaimable */
+#define __GFP_RCLM_BITS (__GFP_USER|__GFP_KERNRCLM)
+
#define __GFP_BITS_SHIFT 20 /* Room for 20 __GFP_FOO bits */
#define __GFP_BITS_MASK ((1 << __GFP_BITS_SHIFT) - 1)
@@ -48,14 +58,15 @@ struct vm_area_struct;
#define GFP_LEVEL_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS| \
__GFP_COLD|__GFP_NOWARN|__GFP_REPEAT| \
__GFP_NOFAIL|__GFP_NORETRY|__GFP_NO_GROW|__GFP_COMP| \
- __GFP_NOMEMALLOC|__GFP_NORECLAIM)
+ __GFP_NOMEMALLOC|__GFP_KERNRCLM|__GFP_USER)
#define GFP_ATOMIC (__GFP_HIGH)
#define GFP_NOIO (__GFP_WAIT)
#define GFP_NOFS (__GFP_WAIT | __GFP_IO)
#define GFP_KERNEL (__GFP_WAIT | __GFP_IO | __GFP_FS)
-#define GFP_USER (__GFP_WAIT | __GFP_IO | __GFP_FS)
-#define GFP_HIGHUSER (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HIGHMEM)
+#define GFP_USER (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_USER)
+#define GFP_HIGHUSER (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HIGHMEM | \
+ __GFP_USER)
/* Flag - indicates that the buffer will be suitable for DMA. Ignored on some
platforms, used as appropriate on others */
next prev parent reply other threads:[~2005-09-27 22:02 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-09-26 20:01 [PATCH 0/9] fragmentation avoidance Joel Schopp
2005-09-26 20:03 ` [PATCH 1/9] add defrag flags Joel Schopp
2005-09-27 0:16 ` Kyle Moffett
2005-09-27 0:24 ` Dave Hansen
2005-09-27 0:43 ` Kyle Moffett
2005-09-27 5:44 ` Paul Jackson
2005-09-27 13:34 ` Mel Gorman
2005-09-27 16:26 ` [Lhms-devel] " Paul Jackson
2005-09-27 18:38 ` Joel Schopp
2005-09-27 19:30 ` Paul Jackson
2005-09-27 21:00 ` [Lhms-devel] " Joel Schopp
2005-09-27 21:23 ` Paul Jackson
2005-09-27 22:03 ` Joel Schopp [this message]
2005-09-27 22:45 ` Paul Jackson
2005-09-26 20:05 ` [PATCH 2/9] declare defrag structs Joel Schopp
2005-09-26 20:06 ` [PATCH 3/9] initialize defrag Joel Schopp
2005-09-26 20:09 ` [PATCH 4/9] defrag helper functions Joel Schopp
2005-09-26 22:29 ` Alex Bligh - linux-kernel
2005-09-27 16:08 ` Joel Schopp
2005-09-26 20:11 ` [PATCH 5/9] propagate defrag alloc types Joel Schopp
2005-09-26 20:13 ` [PATCH 6/9] fragmentation avoidance core Joel Schopp
2005-09-26 20:14 ` [PATCH 7/9] try harder on large allocations Joel Schopp
2005-09-27 7:21 ` Coywolf Qi Hunt
2005-09-27 16:17 ` Joel Schopp
2005-09-26 20:16 ` [PATCH 8/9] defrag fallback Joel Schopp
2005-09-26 20:17 ` [PATCH 9/9] free memory is user reclaimable Joel Schopp
2005-09-26 20:19 ` [PATCH 10/9] percpu splitout Joel Schopp
2005-09-26 21:49 ` [Lhms-devel] [PATCH 0/9] fragmentation avoidance Joel Schopp
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