This patch makes the comments match for icache,dcache,dqcache shrink
functions. Initially the comment stated that a priority of 0 could be used,
but after looking into mm/vmscan.c::shrink_caches this cannot be true. So
the comment now states that 1 is the highest priority. This appears __really
true as at priority 1 all of the cache possible is removed.
Also shrink_dqcache_memory now uses the count variable like everyone else.
Possibly incorrect __GFP_FS check added to the dqcache function. but again
consistancy is my goal.
Another dqcache issue in that the dqcache was being shrunk at priority+1
rather than at priority, this looked suspect, and with no comment around the
code, it to has been remanded to consistancy.
Well, here goes. Any comments and/or b#$chslaps welcome. This is my first
attempted patch after studying the VFS layer for a while, so please be
(fairly) kind.
Craig.
diff -urN linux/fs/dcache.c linux.mt/fs/dcache.c
--- linux/fs/dcache.c Sat Dec 1 17:21:03 2001
+++ linux.mt/fs/dcache.c Wed Dec 5 16:13:38 2001
@@ -543,7 +543,7 @@
* too much.
*
* Priority:
- * 0 - very urgent: shrink everything
+ * 1 - very urgent: shrink everything
* ...
* 6 - base-level: try to shrink a bit.
*/
diff -urN linux/fs/dquot.c linux.mt/fs/dquot.c
--- linux/fs/dquot.c Thu Nov 22 13:38:31 2001
+++ linux.mt/fs/dquot.c Wed Dec 5 17:07:23 2001
@@ -407,11 +407,30 @@
head = free_dquots.prev;
}
}
+/*
+ * This is called from kswapd when we think we need some
+ * more memory, but aren't really sure how much. So we
+ * carefully try to free a _bit_ of our dqcache, but not
+ * too much.
+ *
+ * Priority:
+ * 1 - very urgent: shrink everything
+ * ...
+ * 6 - base-level: try to shrink a bit.
+ */
int shrink_dqcache_memory(int priority, unsigned int gfp_mask)
{
+ int count = 0;
+
lock_kernel();
- prune_dqcache(nr_free_dquots / (priority + 1));
+
+ if (!(gfp_mask & __GFP_FS))
+ return 0;
+
+ count = nr_free_dquots / priority;
+
+ prune_dqcache(count);
unlock_kernel();
kmem_cache_shrink(dquot_cachep);
return 0;
diff -urN linux/fs/inode.c linux.mt/fs/inode.c
--- linux/fs/inode.c Sat Dec 1 17:21:03 2001
+++ linux.mt/fs/inode.c Wed Dec 5 16:37:25 2001
@@ -707,7 +707,17 @@
if (goal)
schedule_task(&unused_inodes_flush_task);
}
-
+/*
+ * This is called from kswapd when we think we need some
+ * more memory, but aren't really sure how much. So we
+ * carefully try to free a _bit_ of our icache, but not
+ * too much.
+ *
+ * Priority:
+ * 1 - very urgent: shrink everything
+ * ...
+ * 6 - base-level: try to shrink a bit.
+ */
int shrink_icache_memory(int priority, int gfp_mask)
{
int count = 0;
locking issue with return 0; inside the lock/unlock_kernel calls. previous
patch is crap. use this one instead.
Craig.
diff -urN linux/fs/dcache.c linux.mt/fs/dcache.c
--- linux/fs/dcache.c Sat Dec 1 17:21:03 2001
+++ linux.mt/fs/dcache.c Wed Dec 5 16:13:38 2001
@@ -543,7 +543,7 @@
* too much.
*
* Priority:
- * 0 - very urgent: shrink everything
+ * 1 - very urgent: shrink everything
* ...
* 6 - base-level: try to shrink a bit.
*/
diff -urN linux/fs/dquot.c linux.mt/fs/dquot.c
--- linux/fs/dquot.c Thu Nov 22 13:38:31 2001
+++ linux.mt/fs/dquot.c Wed Dec 5 17:46:29 2001
@@ -407,11 +407,31 @@
head = free_dquots.prev;
}
}
+/*
+ * This is called from kswapd when we think we need some
+ * more memory, but aren't really sure how much. So we
+ * carefully try to free a _bit_ of our dqcache, but not
+ * too much.
+ *
+ * Priority:
+ * 1 - very urgent: shrink everything
+ * ...
+ * 6 - base-level: try to shrink a bit.
+ */
int shrink_dqcache_memory(int priority, unsigned int gfp_mask)
{
+ int count = 0;
+
+
+ if (!(gfp_mask & __GFP_FS))
+ return 0;
+
lock_kernel();
- prune_dqcache(nr_free_dquots / (priority + 1));
+
+ count = nr_free_dquots / priority;
+
+ prune_dqcache(count);
unlock_kernel();
kmem_cache_shrink(dquot_cachep);
return 0;
diff -urN linux/fs/inode.c linux.mt/fs/inode.c
--- linux/fs/inode.c Sat Dec 1 17:21:03 2001
+++ linux.mt/fs/inode.c Wed Dec 5 16:37:25 2001
@@ -707,7 +707,17 @@
if (goal)
schedule_task(&unused_inodes_flush_task);
}
-
+/*
+ * This is called from kswapd when we think we need some
+ * more memory, but aren't really sure how much. So we
+ * carefully try to free a _bit_ of our icache, but not
+ * too much.
+ *
+ * Priority:
+ * 1 - very urgent: shrink everything
+ * ...
+ * 6 - base-level: try to shrink a bit.
+ */
int shrink_icache_memory(int priority, int gfp_mask)
{
int count = 0;
Hello,
> This patch makes the comments match for icache,dcache,dqcache shrink
> functions. Initially the comment stated that a priority of 0 could be used,
> but after looking into mm/vmscan.c::shrink_caches this cannot be true. So
> the comment now states that 1 is the highest priority. This appears __really
> true as at priority 1 all of the cache possible is removed.
>
> Also shrink_dqcache_memory now uses the count variable like everyone else.
>
> Possibly incorrect __GFP_FS check added to the dqcache function. but again
> consistancy is my goal.
This check really isn't needed for shrink_dqcache() function. This function can
never recurse into fs so there's no need to have __GFP_FS set.
> Another dqcache issue in that the dqcache was being shrunk at priority+1
> rather than at priority, this looked suspect, and with no comment around the
> code, it to has been remanded to consistancy.
OK :). If I remeber well I saw 'priority' could be 0 somewhere in the comment
and so I added +1 to avoid division by zero. But you're right that code in vmscan.c
actually never calls the functions with priority == 0.
Honza
Well here is the fixed patch with __GFP_FS check removed from dqcache.
Thanks for the note.
Craig
> > Possibly incorrect __GFP_FS check added to the dqcache function. but
> > again consistancy is my goal.
>
> This check really isn't needed for shrink_dqcache() function. This
> function can never recurse into fs so there's no need to have __GFP_FS set.
diff -urN linux/fs/dcache.c linux.mt/fs/dcache.c
--- linux/fs/dcache.c Wed Dec 5 18:22:42 2001
+++ linux.mt/fs/dcache.c Wed Dec 5 18:22:26 2001
@@ -543,7 +543,7 @@
* too much.
*
* Priority:
- * 0 - very urgent: shrink everything
+ * 1 - very urgent: shrink everything
* ...
* 6 - base-level: try to shrink a bit.
*/
diff -urN linux/fs/dquot.c linux.mt/fs/dquot.c
--- linux/fs/dquot.c Wed Dec 5 18:22:42 2001
+++ linux.mt/fs/dquot.c Thu Dec 6 10:09:24 2001
@@ -407,11 +407,28 @@
head = free_dquots.prev;
}
}
+/*
+ * This is called from kswapd when we think we need some
+ * more memory, but aren't really sure how much. So we
+ * carefully try to free a _bit_ of our dqcache, but not
+ * too much.
+ *
+ * Priority:
+ * 1 - very urgent: shrink everything
+ * ...
+ * 6 - base-level: try to shrink a bit.
+ */
int shrink_dqcache_memory(int priority, unsigned int gfp_mask)
{
+ int count = 0;
+
+
lock_kernel();
- prune_dqcache(nr_free_dquots / (priority + 1));
+
+ count = nr_free_dquots / priority;
+
+ prune_dqcache(count);
unlock_kernel();
kmem_cache_shrink(dquot_cachep);
return 0;
diff -urN linux/fs/inode.c linux.mt/fs/inode.c
--- linux/fs/inode.c Wed Dec 5 18:22:42 2001
+++ linux.mt/fs/inode.c Wed Dec 5 18:22:26 2001
@@ -707,7 +707,17 @@
if (goal)
schedule_task(&unused_inodes_flush_task);
}
-
+/*
+ * This is called from kswapd when we think we need some
+ * more memory, but aren't really sure how much. So we
+ * carefully try to free a _bit_ of our icache, but not
+ * too much.
+ *
+ * Priority:
+ * 1 - very urgent: shrink everything
+ * ...
+ * 6 - base-level: try to shrink a bit.
+ */
int shrink_icache_memory(int priority, int gfp_mask)
{
int count = 0;