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Merge branch 'writeback' of git://git.kernel.dk/linux-2.6-block

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* 'writeback' of git://git.kernel.dk/linux-2.6-block:
  writeback: writeback_inodes_sb() should use bdi_start_writeback()
  writeback: don't delay inodes redirtied by a fast dirtier
  writeback: make the super_block pinning more efficient
  writeback: don't resort for a single super_block in move_expired_inodes()
  writeback: move inodes from one super_block together
  writeback: get rid to incorrect references to pdflush in comments
  writeback: improve readability of the wb_writeback() continue/break logic
  writeback: cleanup writeback_single_inode()
  writeback: kupdate writeback shall not stop when more io is possible
  writeback: stop background writeback when below background threshold
  writeback: balance_dirty_pages() shall write more than dirtied pages
  fs: Fix busyloop in wb_writeback()
This commit is contained in:
Linus Torvalds
2009-09-25 09:27:30 -07:00
parent 53cddfcc0e 56a131dcf7
commit 6d7f18f6ea
5 changed files with 142 additions and 72 deletions
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30
mm/page-writeback.c
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@@ -44,18 +44,21 @@ static long ratelimit_pages = 32;
/*
* When balance_dirty_pages decides that the caller needs to perform some
* non-background writeback, this is how many pages it will attempt to write.
* It should be somewhat larger than RATELIMIT_PAGES to ensure that reasonably
* It should be somewhat larger than dirtied pages to ensure that reasonably
* large amounts of I/O are submitted.
*/
static inline long sync_writeback_pages(void)
static inline long sync_writeback_pages(unsigned long dirtied)
{
return ratelimit_pages + ratelimit_pages / 2;
if (dirtied < ratelimit_pages)
dirtied = ratelimit_pages;
return dirtied + dirtied / 2;
}
/* The following parameters are exported via /proc/sys/vm */
/*
* Start background writeback (via pdflush) at this percentage
* Start background writeback (via writeback threads) at this percentage
*/
int dirty_background_ratio = 10;
@@ -474,10 +477,11 @@ get_dirty_limits(unsigned long *pbackground, unsigned long *pdirty,
* balance_dirty_pages() must be called by processes which are generating dirty
* data. It looks at the number of dirty pages in the machine and will force
* the caller to perform writeback if the system is over `vm_dirty_ratio'.
* If we're over `background_thresh' then pdflush is woken to perform some
* writeout.
* If we're over `background_thresh' then the writeback threads are woken to
* perform some writeout.
*/
static void balance_dirty_pages(struct address_space *mapping)
static void balance_dirty_pages(struct address_space *mapping,
unsigned long write_chunk)
{
long nr_reclaimable, bdi_nr_reclaimable;
long nr_writeback, bdi_nr_writeback;
@@ -485,7 +489,6 @@ static void balance_dirty_pages(struct address_space *mapping)
unsigned long dirty_thresh;
unsigned long bdi_thresh;
unsigned long pages_written = 0;
unsigned long write_chunk = sync_writeback_pages();
unsigned long pause = 1;
struct backing_dev_info *bdi = mapping->backing_dev_info;
@@ -579,7 +582,7 @@ static void balance_dirty_pages(struct address_space *mapping)
bdi->dirty_exceeded = 0;
if (writeback_in_progress(bdi))
return; /* pdflush is already working this queue */
return;
/*
* In laptop mode, we wait until hitting the higher threshold before
@@ -590,10 +593,10 @@ static void balance_dirty_pages(struct address_space *mapping)
* background_thresh, to keep the amount of dirty memory low.
*/
if ((laptop_mode && pages_written) ||
(!laptop_mode && ((nr_writeback = global_page_state(NR_FILE_DIRTY)
+ global_page_state(NR_UNSTABLE_NFS))
(!laptop_mode && ((global_page_state(NR_FILE_DIRTY)
+ global_page_state(NR_UNSTABLE_NFS))
> background_thresh)))
bdi_start_writeback(bdi, nr_writeback);
bdi_start_writeback(bdi, 0);
}
void set_page_dirty_balance(struct page *page, int page_mkwrite)
@@ -640,9 +643,10 @@ void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
p = &__get_cpu_var(bdp_ratelimits);
*p += nr_pages_dirtied;
if (unlikely(*p >= ratelimit)) {
ratelimit = sync_writeback_pages(*p);
*p = 0;
preempt_enable();
balance_dirty_pages(mapping);
balance_dirty_pages(mapping, ratelimit);
return;
}
preempt_enable();