[Patch] tmpfs accounting cleanup for -ac series
Hi Alan,
While looking at the -ac version of ramfs I noticed that there is a
new address operation introduced which I can use to cleanup shmem.
This patch throws away some magic recalculation and makes the
accounting of shmem accurate.
It also encapsulates all accesses to the superblock_info into a macro.
The patch is on top of my previous ones.
Greetings
Christoph
diff -uNr 4-ac9/fs/proc/proc_misc.c c/fs/proc/proc_misc.c
--- 4-ac9/fs/proc/proc_misc.c Thu May 17 13:17:37 2001
+++ c/fs/proc/proc_misc.c Thu May 17 13:11:30 2001
@@ -140,17 +140,9 @@
{
struct sysinfo i;
int len;
- unsigned int cached, shmem;
+ unsigned int cached;
- /*
-* There may be some inconsistency because shmem_nrpages
-* update is delayed to page_cache_size
-* We make sure the cached value does not get below zero
-*/
- cached = atomic_read(_cache_size);
- shmem = atomic_read(_nrpages);
- if (shmem < cached)
- cached -= shmem;
+ cached = atomic_read(_cache_size) - atomic_read(_nrpages);
/*
* display in kilobytes.
diff -uNr 4-ac9/mm/mmap.c c/mm/mmap.c
--- 4-ac9/mm/mmap.c Thu May 17 13:17:37 2001
+++ c/mm/mmap.c Thu May 17 10:54:22 2001
@@ -56,24 +56,14 @@
*/
long free;
- unsigned long cached, shmem;
-
- /*
-* There may be some inconsistency because shmem_nrpages
-* update is delayed to the page_cache_size
-* We make sure the cached value does not get below zero
-*/
- cached = atomic_read(_cache_size);
- shmem = atomic_read(_nrpages);
- if (cached > shmem)
- cached -= shmem;
/* Sometimes we want to use more memory than we have. */
if (sysctl_overcommit_memory)
return 1;
free = atomic_read(_pages);
- free += cached;
+ free += atomic_read(_cache_size) ;
+ free -= atomic_read(_nrpages);
free += nr_free_pages();
free += nr_swap_pages;
diff -uNr 4-ac9/mm/shmem.c c/mm/shmem.c
--- 4-ac9/mm/shmem.cThu May 17 13:17:37 2001
+++ c/mm/shmem.cThu May 17 10:54:03 2001
@@ -35,6 +35,8 @@
#define ENTRIES_PER_PAGE (PAGE_SIZE/sizeof(unsigned long))
+#define SHMEM_SB(sb) (>u.shmem_sb)
+
static struct super_operations shmem_ops;
static struct address_space_operations shmem_aops;
static struct file_operations shmem_file_operations;
@@ -50,44 +52,6 @@
#define BLOCKS_PER_PAGE (PAGE_SIZE/512)
/*
- * shmem_recalc_inode - recalculate the size of an inode
- *
- * @inode: inode to recalc
- * @swap: additional swap pages freed externally
- *
- * We have to calculate the free blocks since the mm can drop pages
- * behind our back
- *
- * But we know that normally
- * inodes->i_blocks/BLOCKS_PER_PAGE ==
- * inode->i_mapping->nrpages + info->swapped
- *
- * So the mm freed
- * inodes->i_blocks/BLOCKS_PER_PAGE -
- * (inode->i_mapping->nrpages + info->swapped)
- *
- * It has to be called with the spinlock held.
- *
- * The swap parameter is a performance hack for truncate.
- */
-
-static void shmem_recalc_inode(struct inode * inode, unsigned long swap)
-{
- unsigned long freed;
-
- freed = (inode->i_blocks/BLOCKS_PER_PAGE) -
- (inode->i_mapping->nrpages + SHMEM_I(inode)->swapped);
- if (freed){
- struct shmem_sb_info * info = >i_sb->u.shmem_sb;
- inode->i_blocks -= freed*BLOCKS_PER_PAGE;
- spin_lock (>stat_lock);
- info->free_blocks += freed;
- spin_unlock (>stat_lock);
- atomic_sub(freed-swap, _nrpages);
- }
-}
-
-/*
* shmem_swp_entry - find the swap vector position in the info structure
*
* @info: info structure for the inode
@@ -318,6 +282,7 @@
unsigned long index;
unsigned long freed = 0;
struct shmem_inode_info * info = SHMEM_I(inode);
+ struct shmem_sb_info * sbinfo = SHMEM_SB(inode->i_sb);
down(>sem);
inode->i_ctime = inode->i_mtime = CURRENT_TIME;
@@ -328,14 +293,28 @@
freed += shmem_truncate_indirect(info, index);
info->swapped -= freed;
- shmem_recalc_inode(inode, freed);
+ spin_lock(>stat_lock);
+ sbinfo->free_blocks += freed;
+ spin_unlock(>stat_lock);
spin_unlock (>lock);
up(>sem);
}
+static void shmem_truncatepage(struct page *page)
+{
+ struct inode *inode = (struct inode *)page->mapping->host;
+ struct shmem_sb_info * sbinfo = SHMEM_SB(inode->i_sb);
+
+ inode->i_blocks -= BLOCKS_PER_PAGE;
+ spin_lock (>stat_lock);
+ sbinfo->free_blocks++;
+ spin_unlock (>stat_lock);
+ atomic_dec(_nrpages);
+}
+
static void shmem_delete_inode(struct inode * inode)
{
- struct shmem_sb_info *info = >i_sb->u.shmem_sb;
+ struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
inode->i_size =
[Patch] tmpfs accounting cleanup for -ac series
Hi Alan,
While looking at the -ac version of ramfs I noticed that there is a
new address operation introduced which I can use to cleanup shmem.
This patch throws away some magic recalculation and makes the
accounting of shmem accurate.
It also encapsulates all accesses to the superblock_info into a macro.
The patch is on top of my previous ones.
Greetings
Christoph
diff -uNr 4-ac9/fs/proc/proc_misc.c c/fs/proc/proc_misc.c
--- 4-ac9/fs/proc/proc_misc.c Thu May 17 13:17:37 2001
+++ c/fs/proc/proc_misc.c Thu May 17 13:11:30 2001
@@ -140,17 +140,9 @@
{
struct sysinfo i;
int len;
- unsigned int cached, shmem;
+ unsigned int cached;
- /*
-* There may be some inconsistency because shmem_nrpages
-* update is delayed to page_cache_size
-* We make sure the cached value does not get below zero
-*/
- cached = atomic_read(page_cache_size);
- shmem = atomic_read(shmem_nrpages);
- if (shmem cached)
- cached -= shmem;
+ cached = atomic_read(page_cache_size) - atomic_read(shmem_nrpages);
/*
* display in kilobytes.
diff -uNr 4-ac9/mm/mmap.c c/mm/mmap.c
--- 4-ac9/mm/mmap.c Thu May 17 13:17:37 2001
+++ c/mm/mmap.c Thu May 17 10:54:22 2001
@@ -56,24 +56,14 @@
*/
long free;
- unsigned long cached, shmem;
-
- /*
-* There may be some inconsistency because shmem_nrpages
-* update is delayed to the page_cache_size
-* We make sure the cached value does not get below zero
-*/
- cached = atomic_read(page_cache_size);
- shmem = atomic_read(shmem_nrpages);
- if (cached shmem)
- cached -= shmem;
/* Sometimes we want to use more memory than we have. */
if (sysctl_overcommit_memory)
return 1;
free = atomic_read(buffermem_pages);
- free += cached;
+ free += atomic_read(page_cache_size) ;
+ free -= atomic_read(shmem_nrpages);
free += nr_free_pages();
free += nr_swap_pages;
diff -uNr 4-ac9/mm/shmem.c c/mm/shmem.c
--- 4-ac9/mm/shmem.cThu May 17 13:17:37 2001
+++ c/mm/shmem.cThu May 17 10:54:03 2001
@@ -35,6 +35,8 @@
#define ENTRIES_PER_PAGE (PAGE_SIZE/sizeof(unsigned long))
+#define SHMEM_SB(sb) (sb-u.shmem_sb)
+
static struct super_operations shmem_ops;
static struct address_space_operations shmem_aops;
static struct file_operations shmem_file_operations;
@@ -50,44 +52,6 @@
#define BLOCKS_PER_PAGE (PAGE_SIZE/512)
/*
- * shmem_recalc_inode - recalculate the size of an inode
- *
- * @inode: inode to recalc
- * @swap: additional swap pages freed externally
- *
- * We have to calculate the free blocks since the mm can drop pages
- * behind our back
- *
- * But we know that normally
- * inodes-i_blocks/BLOCKS_PER_PAGE ==
- * inode-i_mapping-nrpages + info-swapped
- *
- * So the mm freed
- * inodes-i_blocks/BLOCKS_PER_PAGE -
- * (inode-i_mapping-nrpages + info-swapped)
- *
- * It has to be called with the spinlock held.
- *
- * The swap parameter is a performance hack for truncate.
- */
-
-static void shmem_recalc_inode(struct inode * inode, unsigned long swap)
-{
- unsigned long freed;
-
- freed = (inode-i_blocks/BLOCKS_PER_PAGE) -
- (inode-i_mapping-nrpages + SHMEM_I(inode)-swapped);
- if (freed){
- struct shmem_sb_info * info = inode-i_sb-u.shmem_sb;
- inode-i_blocks -= freed*BLOCKS_PER_PAGE;
- spin_lock (info-stat_lock);
- info-free_blocks += freed;
- spin_unlock (info-stat_lock);
- atomic_sub(freed-swap, shmem_nrpages);
- }
-}
-
-/*
* shmem_swp_entry - find the swap vector position in the info structure
*
* @info: info structure for the inode
@@ -318,6 +282,7 @@
unsigned long index;
unsigned long freed = 0;
struct shmem_inode_info * info = SHMEM_I(inode);
+ struct shmem_sb_info * sbinfo = SHMEM_SB(inode-i_sb);
down(info-sem);
inode-i_ctime = inode-i_mtime = CURRENT_TIME;
@@ -328,14 +293,28 @@
freed += shmem_truncate_indirect(info, index);
info-swapped -= freed;
- shmem_recalc_inode(inode, freed);
+ spin_lock(sbinfo-stat_lock);
+ sbinfo-free_blocks += freed;
+ spin_unlock(sbinfo-stat_lock);
spin_unlock (info-lock);
up(info-sem);
}
+static void shmem_truncatepage(struct page *page)
+{
+ struct inode *inode = (struct inode *)page-mapping-host;
+ struct shmem_sb_info * sbinfo = SHMEM_SB(inode-i_sb);
+
+ inode-i_blocks -= BLOCKS_PER_PAGE;
+ spin_lock (sbinfo-stat_lock);
+ sbinfo-free_blocks++;
+ spin_unlock (sbinfo-stat_lock);
+ atomic_dec(shmem_nrpages);
+}
+
static void shmem_delete_inode(struct inode * inode)
{
- struct shmem_sb_info *info = inode-i_sb-u.shmem_sb;
+
