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authorDmitry Torokhov <dtor@vmware.com>2010-06-04 14:14:52 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-06-04 15:21:44 -0700
commit55adaa495edc429be84399f83df80dfb7f36598b (patch)
treee7cf5e2ac61ebfa799484c11e148150c51ec0f60
parentf76f5d71048e116f76d2eb02226b01d50890e2f4 (diff)
vmware balloon: clamp number of collected non-balloonable pages
Limit number of accumulated non-balloonable pages during inflation cycle, otherwise there is a chance we will be spinning and growing the list forever. This happens during torture tests when balloon target changes while we are in the middle of inflation cycle and monitor starts refusing to lock pages (since they are not needed anymore). Signed-off-by: Dmitry Torokhov <dtor@vmware.com> Acked-by: Bhavesh Davda <bhavesh@vmware.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/misc/vmware_balloon.c18
1 files changed, 15 insertions, 3 deletions
diff --git a/drivers/misc/vmware_balloon.c b/drivers/misc/vmware_balloon.c
index db9cd0240c6f..2a1e804a71aa 100644
--- a/drivers/misc/vmware_balloon.c
+++ b/drivers/misc/vmware_balloon.c
@@ -45,7 +45,7 @@
MODULE_AUTHOR("VMware, Inc.");
MODULE_DESCRIPTION("VMware Memory Control (Balloon) Driver");
-MODULE_VERSION("1.2.1.0-K");
+MODULE_VERSION("1.2.1.1-k");
MODULE_ALIAS("dmi:*:svnVMware*:*");
MODULE_ALIAS("vmware_vmmemctl");
MODULE_LICENSE("GPL");
@@ -101,6 +101,8 @@ MODULE_LICENSE("GPL");
/* Maximum number of page allocations without yielding processor */
#define VMW_BALLOON_YIELD_THRESHOLD 1024
+/* Maximum number of refused pages we accumulate during inflation cycle */
+#define VMW_BALLOON_MAX_REFUSED 16
/*
* Hypervisor communication port definitions.
@@ -183,6 +185,7 @@ struct vmballoon {
/* transient list of non-balloonable pages */
struct list_head refused_pages;
+ unsigned int n_refused_pages;
/* balloon size in pages */
unsigned int size;
@@ -428,14 +431,21 @@ static int vmballoon_reserve_page(struct vmballoon *b, bool can_sleep)
/* inform monitor */
locked = vmballoon_send_lock_page(b, page_to_pfn(page));
if (!locked) {
+ STATS_INC(b->stats.refused_alloc);
+
if (b->reset_required) {
__free_page(page);
return -EIO;
}
- /* place on list of non-balloonable pages, retry allocation */
+ /*
+ * Place page on the list of non-balloonable pages
+ * and retry allocation, unless we already accumulated
+ * too many of them, in which case take a breather.
+ */
list_add(&page->lru, &b->refused_pages);
- STATS_INC(b->stats.refused_alloc);
+ if (++b->n_refused_pages >= VMW_BALLOON_MAX_REFUSED)
+ return -EIO;
}
} while (!locked);
@@ -483,6 +493,8 @@ static void vmballoon_release_refused_pages(struct vmballoon *b)
__free_page(page);
STATS_INC(b->stats.refused_free);
}
+
+ b->n_refused_pages = 0;
}
/*