Commit e4ad08fe authored by Miklos Szeredi's avatar Miklos Szeredi Committed by Linus Torvalds

mm: bdi: add separate writeback accounting capability

Add a new BDI capability flag: BDI_CAP_NO_ACCT_WB.  If this flag is
set, then don't update the per-bdi writeback stats from
test_set_page_writeback() and test_clear_page_writeback().

Misc cleanups:

 - convert bdi_cap_writeback_dirty() and friends to static inline functions
 - create a flag that includes all three dirty/writeback related flags,
   since almst all users will want to have them toghether
Signed-off-by: default avatarMiklos Szeredi <mszeredi@suse.cz>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 76f1418b
......@@ -47,7 +47,7 @@ static const struct address_space_operations configfs_aops = {
static struct backing_dev_info configfs_backing_dev_info = {
.ra_pages = 0, /* No readahead */
.capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
.capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
};
static const struct inode_operations configfs_inode_operations ={
......
......@@ -45,7 +45,7 @@ static const struct inode_operations hugetlbfs_inode_operations;
static struct backing_dev_info hugetlbfs_backing_dev_info = {
.ra_pages = 0, /* No readahead */
.capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
.capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
};
int sysctl_hugetlb_shm_group;
......
......@@ -327,7 +327,7 @@ static void dlmfs_clear_inode(struct inode *inode)
static struct backing_dev_info dlmfs_backing_dev_info = {
.ra_pages = 0, /* No readahead */
.capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
.capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
};
static struct inode *dlmfs_get_root_inode(struct super_block *sb)
......
......@@ -44,7 +44,7 @@ static const struct inode_operations ramfs_dir_inode_operations;
static struct backing_dev_info ramfs_backing_dev_info = {
.ra_pages = 0, /* No readahead */
.capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK |
.capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK |
BDI_CAP_MAP_DIRECT | BDI_CAP_MAP_COPY |
BDI_CAP_READ_MAP | BDI_CAP_WRITE_MAP | BDI_CAP_EXEC_MAP,
};
......
......@@ -30,7 +30,7 @@ static const struct address_space_operations sysfs_aops = {
static struct backing_dev_info sysfs_backing_dev_info = {
.ra_pages = 0, /* No readahead */
.capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
.capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
};
static const struct inode_operations sysfs_inode_operations ={
......
......@@ -12,6 +12,7 @@
#include <linux/log2.h>
#include <linux/proportions.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <asm/atomic.h>
struct page;
......@@ -151,22 +152,43 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio);
/*
* Flags in backing_dev_info::capability
* - The first two flags control whether dirty pages will contribute to the
* VM's accounting and whether writepages() should be called for dirty pages
* (something that would not, for example, be appropriate for ramfs)
* - These flags let !MMU mmap() govern direct device mapping vs immediate
* copying more easily for MAP_PRIVATE, especially for ROM filesystems
*
* The first three flags control whether dirty pages will contribute to the
* VM's accounting and whether writepages() should be called for dirty pages
* (something that would not, for example, be appropriate for ramfs)
*
* WARNING: these flags are closely related and should not normally be
* used separately. The BDI_CAP_NO_ACCT_AND_WRITEBACK combines these
* three flags into a single convenience macro.
*
* BDI_CAP_NO_ACCT_DIRTY: Dirty pages shouldn't contribute to accounting
* BDI_CAP_NO_WRITEBACK: Don't write pages back
* BDI_CAP_NO_ACCT_WB: Don't automatically account writeback pages
*
* These flags let !MMU mmap() govern direct device mapping vs immediate
* copying more easily for MAP_PRIVATE, especially for ROM filesystems.
*
* BDI_CAP_MAP_COPY: Copy can be mapped (MAP_PRIVATE)
* BDI_CAP_MAP_DIRECT: Can be mapped directly (MAP_SHARED)
* BDI_CAP_READ_MAP: Can be mapped for reading
* BDI_CAP_WRITE_MAP: Can be mapped for writing
* BDI_CAP_EXEC_MAP: Can be mapped for execution
*/
#define BDI_CAP_NO_ACCT_DIRTY 0x00000001 /* Dirty pages shouldn't contribute to accounting */
#define BDI_CAP_NO_WRITEBACK 0x00000002 /* Don't write pages back */
#define BDI_CAP_MAP_COPY 0x00000004 /* Copy can be mapped (MAP_PRIVATE) */
#define BDI_CAP_MAP_DIRECT 0x00000008 /* Can be mapped directly (MAP_SHARED) */
#define BDI_CAP_READ_MAP 0x00000010 /* Can be mapped for reading */
#define BDI_CAP_WRITE_MAP 0x00000020 /* Can be mapped for writing */
#define BDI_CAP_EXEC_MAP 0x00000040 /* Can be mapped for execution */
#define BDI_CAP_NO_ACCT_DIRTY 0x00000001
#define BDI_CAP_NO_WRITEBACK 0x00000002
#define BDI_CAP_MAP_COPY 0x00000004
#define BDI_CAP_MAP_DIRECT 0x00000008
#define BDI_CAP_READ_MAP 0x00000010
#define BDI_CAP_WRITE_MAP 0x00000020
#define BDI_CAP_EXEC_MAP 0x00000040
#define BDI_CAP_NO_ACCT_WB 0x00000080
#define BDI_CAP_VMFLAGS \
(BDI_CAP_READ_MAP | BDI_CAP_WRITE_MAP | BDI_CAP_EXEC_MAP)
#define BDI_CAP_NO_ACCT_AND_WRITEBACK \
(BDI_CAP_NO_WRITEBACK | BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_ACCT_WB)
#if defined(VM_MAYREAD) && \
(BDI_CAP_READ_MAP != VM_MAYREAD || \
BDI_CAP_WRITE_MAP != VM_MAYWRITE || \
......@@ -206,17 +228,32 @@ void clear_bdi_congested(struct backing_dev_info *bdi, int rw);
void set_bdi_congested(struct backing_dev_info *bdi, int rw);
long congestion_wait(int rw, long timeout);
#define bdi_cap_writeback_dirty(bdi) \
(!((bdi)->capabilities & BDI_CAP_NO_WRITEBACK))
#define bdi_cap_account_dirty(bdi) \
(!((bdi)->capabilities & BDI_CAP_NO_ACCT_DIRTY))
static inline bool bdi_cap_writeback_dirty(struct backing_dev_info *bdi)
{
return !(bdi->capabilities & BDI_CAP_NO_WRITEBACK);
}
static inline bool bdi_cap_account_dirty(struct backing_dev_info *bdi)
{
return !(bdi->capabilities & BDI_CAP_NO_ACCT_DIRTY);
}
#define mapping_cap_writeback_dirty(mapping) \
bdi_cap_writeback_dirty((mapping)->backing_dev_info)
static inline bool bdi_cap_account_writeback(struct backing_dev_info *bdi)
{
/* Paranoia: BDI_CAP_NO_WRITEBACK implies BDI_CAP_NO_ACCT_WB */
return !(bdi->capabilities & (BDI_CAP_NO_ACCT_WB |
BDI_CAP_NO_WRITEBACK));
}
#define mapping_cap_account_dirty(mapping) \
bdi_cap_account_dirty((mapping)->backing_dev_info)
static inline bool mapping_cap_writeback_dirty(struct address_space *mapping)
{
return bdi_cap_writeback_dirty(mapping->backing_dev_info);
}
static inline bool mapping_cap_account_dirty(struct address_space *mapping)
{
return bdi_cap_account_dirty(mapping->backing_dev_info);
}
#endif /* _LINUX_BACKING_DEV_H */
......@@ -575,7 +575,7 @@ static struct inode_operations cgroup_dir_inode_operations;
static struct file_operations proc_cgroupstats_operations;
static struct backing_dev_info cgroup_backing_dev_info = {
.capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
.capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
};
static struct inode *cgroup_new_inode(mode_t mode, struct super_block *sb)
......
......@@ -1246,7 +1246,7 @@ int test_clear_page_writeback(struct page *page)
radix_tree_tag_clear(&mapping->page_tree,
page_index(page),
PAGECACHE_TAG_WRITEBACK);
if (bdi_cap_writeback_dirty(bdi)) {
if (bdi_cap_account_writeback(bdi)) {
__dec_bdi_stat(bdi, BDI_WRITEBACK);
__bdi_writeout_inc(bdi);
}
......@@ -1275,7 +1275,7 @@ int test_set_page_writeback(struct page *page)
radix_tree_tag_set(&mapping->page_tree,
page_index(page),
PAGECACHE_TAG_WRITEBACK);
if (bdi_cap_writeback_dirty(bdi))
if (bdi_cap_account_writeback(bdi))
__inc_bdi_stat(bdi, BDI_WRITEBACK);
}
if (!PageDirty(page))
......
......@@ -201,7 +201,7 @@ static struct vm_operations_struct shmem_vm_ops;
static struct backing_dev_info shmem_backing_dev_info __read_mostly = {
.ra_pages = 0, /* No readahead */
.capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
.capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
.unplug_io_fn = default_unplug_io_fn,
};
......
......@@ -33,7 +33,7 @@ static const struct address_space_operations swap_aops = {
};
static struct backing_dev_info swap_backing_dev_info = {
.capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
.capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
.unplug_io_fn = swap_unplug_io_fn,
};
......
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