Imported linux-2.6.27.39 suse/xen patches.

[people/pmueller/ipfire-2.x.git] / src / patches / suse-2.6.27.31 / patches.fixes / mm-nr_pdflush-race-fix.patch

diff --git a/src/patches/suse-2.6.27.31/patches.fixes/mm-nr_pdflush-race-fix.patch b/src/patches/suse-2.6.27.31/patches.fixes/mm-nr_pdflush-race-fix.patch
deleted file mode 100644 (file)
index b0344f1..0000000
--- a/src/patches/suse-2.6.27.31/patches.fixes/mm-nr_pdflush-race-fix.patch
+++ /dev/null
@@ -1,85 +0,0 @@
-Subject: mm: fix pdflush thread creation upper bound.
-From: Peter W. Morreale <pmorreale@novell.com>
-References: bnc#460284
-Patch-upstream: not yet
-    
-    This patch fixes a race on creating pdflush threads.  Without the patch,
-    it is possible to create more than MAX_PDFLUSH_THREADS threads, and this
-    has been observed in practice.
-    
-    The fix involves moving the lock around to protect the check against the
-    thread count and correctly dealing with thread creation failure.
-    
-    Signed-Off-By:   Peter W. Morreale <pmorreale@novell.com>
-Acked-by: Nick Piggin <npiggin@suse.de>
----
----
- mm/pdflush.c |   27 +++++++++++++++++++++------
- 1 file changed, 21 insertions(+), 6 deletions(-)
-
---- a/mm/pdflush.c
-+++ b/mm/pdflush.c
-@@ -98,7 +98,6 @@ static int __pdflush(struct pdflush_work
-       INIT_LIST_HEAD(&my_work->list);
- 
-       spin_lock_irq(&pdflush_lock);
--      nr_pdflush_threads++;
-       for ( ; ; ) {
-               struct pdflush_work *pdf;
- 
-@@ -126,20 +125,23 @@ static int __pdflush(struct pdflush_work
- 
-               (*my_work->fn)(my_work->arg0);
- 
-+              spin_lock_irq(&pdflush_lock);
-+
-               /*
-                * Thread creation: For how long have there been zero
-                * available threads?
-                */
-               if (time_after(jiffies, last_empty_jifs + 1 * HZ)) {
--                      /* unlocked list_empty() test is OK here */
-                       if (list_empty(&pdflush_list)) {
--                              /* unlocked test is OK here */
--                              if (nr_pdflush_threads < MAX_PDFLUSH_THREADS)
-+                              if (nr_pdflush_threads < MAX_PDFLUSH_THREADS) {
-+                                      nr_pdflush_threads++;
-+                                      spin_unlock_irq(&pdflush_lock);
-                                       start_one_pdflush_thread();
-+                                      spin_lock_irq(&pdflush_lock);
-+                              }
-                       }
-               }
- 
--              spin_lock_irq(&pdflush_lock);
-               my_work->fn = NULL;
- 
-               /*
-@@ -226,13 +228,26 @@ int pdflush_operation(void (*fn)(unsigne
- 
- static void start_one_pdflush_thread(void)
- {
--      kthread_run(pdflush, NULL, "pdflush");
-+      struct task_struct *k;
-+
-+      k = kthread_run(pdflush, NULL, "pdflush");
-+      if (unlikely(IS_ERR(k))) {
-+              spin_lock_irq(&pdflush_lock);
-+              nr_pdflush_threads--;
-+              spin_unlock_irq(&pdflush_lock);
-+      }
- }
- 
- static int __init pdflush_init(void)
- {
-       int i;
- 
-+      /*
-+       * Pre-set nr_pdflush_threads...  If we fail to create,
-+       * the count will be decremented.
-+       */
-+      nr_pdflush_threads = MIN_PDFLUSH_THREADS;
-+
-       for (i = 0; i < MIN_PDFLUSH_THREADS; i++)
-               start_one_pdflush_thread();
-       return 0;