On Tuesday 08 October 2002 20:21, Rik van Riel wrote:
> On Tue, 8 Oct 2002 tytso@mit.edu wrote:
> > This first patch creates a generic interface for registering caches with
> > the VM subsystem so that they can react appropriately to memory
> > pressure.
> >
> > +/* BKL must be held */
>
> ... but it isn't. Also, kswapd isn't holding the bkl while
> traversing the list.
>
> > +void register_cache(struct cache_definition *cache)
> > +{
> > + list_add(&cache->link, &cache_definitions);
> > +}
>
> I suspect you'll want a semaphore for the cache_definitions
> list.
My apologies. This has slipped me; I had in fact added a semaphore in a
different branch. Here is a fixed version.
--Andreas.
diff -Nru a/include/linux/cache_def.h b/include/linux/cache_def.h
--- /dev/null Wed Dec 31 16:00:00 1969
+++ b/include/linux/cache_def.h Tue Oct 8 13:52:08 2002
@@ -0,0 +1,15 @@
+/*
+ * linux/cache_def.h
+ * Handling of caches defined in drivers, filesystems, ...
+ *
+ * Copyright (C) 2002 by Andreas Gruenbacher, <a.gruenbacher@computer.org>
+ */
+
+struct cache_definition {
+ const char *name;
+ void (*shrink)(int, unsigned int);
+ struct list_head link;
+};
+
+extern void register_cache(struct cache_definition *);
+extern void unregister_cache(struct cache_definition *);
--- a/kernel/ksyms.c Tue Oct 8 13:52:08 2002
+++ b/kernel/ksyms.c Tue Oct 8 13:52:08 2002
@@ -31,6 +31,7 @@
#include <linux/genhd.h>
#include <linux/blkpg.h>
#include <linux/swap.h>
+#include <linux/cache_def.h>
#include <linux/ctype.h>
#include <linux/file.h>
#include <linux/iobuf.h>
@@ -106,6 +107,8 @@
EXPORT_SYMBOL(kmem_cache_alloc);
EXPORT_SYMBOL(kmem_cache_free);
EXPORT_SYMBOL(kmem_cache_size);
+EXPORT_SYMBOL(register_cache);
+EXPORT_SYMBOL(unregister_cache);
EXPORT_SYMBOL(kmalloc);
EXPORT_SYMBOL(kfree);
EXPORT_SYMBOL(vfree);
--- a/mm/vmscan.c Tue Oct 8 13:52:08 2002
+++ b/mm/vmscan.c Tue Oct 8 13:52:08 2002
@@ -15,6 +15,7 @@
#include <linux/slab.h>
#include <linux/kernel_stat.h>
#include <linux/swap.h>
+#include <linux/cache_def.h>
#include <linux/pagemap.h>
#include <linux/init.h>
#include <linux/highmem.h>
@@ -76,6 +77,39 @@
#define shrink_dqcache_memory(ratio, gfp_mask) do { } while (0)
#endif
+static DECLARE_MUTEX(other_caches_sem);
+static LIST_HEAD(cache_definitions);
+
+void register_cache(struct cache_definition *cache)
+{
+ down(&other_caches_sem);
+ list_add(&cache->link, &cache_definitions);
+ up(&other_caches_sem);
+}
+
+void unregister_cache(struct cache_definition *cache)
+{
+ down(&other_caches_sem);
+ list_del(&cache->link);
+ up(&other_caches_sem);
+}
+
+static void shrink_other_caches(int ratio, int gfp_mask)
+{
+ struct list_head *p;
+
+ down(&other_caches_sem);
+ p = cache_definitions.prev;
+ while (p != &cache_definitions) {
+ struct cache_definition *cache =
+ list_entry(p, struct cache_definition, link);
+
+ cache->shrink(ratio, gfp_mask);
+ p = p->prev;
+ }
+ up(&other_caches_sem);
+}
+
/* Must be called with page's pte_chain_lock held. */
static inline int page_mapping_inuse(struct page * page)
{
@@ -614,6 +648,7 @@
shrink_dcache_memory(ratio, gfp_mask);
shrink_icache_memory(ratio, gfp_mask);
shrink_dqcache_memory(ratio, gfp_mask);
+ shrink_other_caches(ratio, gfp_mask);
return nr_pages;
}
-
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This archive was generated by hypermail 2b29 : Tue Oct 15 2002 - 22:00:26 EST