Reenabled linux-xen, added patches for Xen Kernel Version 2.6.27.31,

[people/pmueller/ipfire-2.x.git] / src / patches / suse-2.6.27.31 / patches.arch / ia64-page-migration.fix

diff --git a/src/patches/suse-2.6.27.31/patches.arch/ia64-page-migration.fix b/src/patches/suse-2.6.27.31/patches.arch/ia64-page-migration.fix
new file mode 100644 (file)
index 0000000..b7515e7
--- /dev/null
+++ b/src/patches/suse-2.6.27.31/patches.arch/ia64-page-migration.fix
@@ -0,0 +1,161 @@
+From: Russ Anderson <rja@sgi.com>
+Subject: ia64: cpe_migrate.ko causes deadlock.
+References: bnc#464676
+
+schedule_on_each_cpu() deadlocks when called from an event thread.
+Change cpe_migrate to use a kthread to avoid the problem.
+
+Signed-off-by: Russ Anderson <rja@sgi.com>
+Acked-by: Raymund Will <rw@suse.de>
+
+---
+ arch/ia64/kernel/cpe_migrate.c |   72 +++++++++++++++++++++++++++++++----------
+ 1 file changed, 56 insertions(+), 16 deletions(-)
+
+Index: linux/arch/ia64/kernel/cpe_migrate.c
+===================================================================
+--- linux.orig/arch/ia64/kernel/cpe_migrate.c  2009-01-09 11:37:47.130269369 -0600
++++ linux/arch/ia64/kernel/cpe_migrate.c       2009-01-09 11:44:43.658280930 -0600
+@@ -22,6 +22,7 @@
+ #include <linux/page-isolation.h>
+ #include <linux/memcontrol.h>
+ #include <linux/kobject.h>
++#include <linux/kthread.h>
+ 
+ #include <asm/page.h>
+ #include <asm/system.h>
+@@ -40,12 +41,15 @@ static struct cpe_info cpe[CE_HISTORY_LE
+ static int cpe_polling_enabled = 1;
+ static int cpe_head;
+ static int cpe_tail;
+-static int work_scheduled;
+ static int mstat_cannot_isolate;
+ static int mstat_failed_to_discard;
+ static int mstat_already_marked;
+ static int mstat_already_on_list;
+ 
++/* IRQ handler notifies this wait queue on receipt of an IRQ */
++DECLARE_WAIT_QUEUE_HEAD(cpe_activate_IRQ_wq);
++static DECLARE_COMPLETION(kthread_cpe_migrated_exited);
++int cpe_active;
+ DEFINE_SPINLOCK(cpe_migrate_lock);
+ 
+ static void
+@@ -159,12 +163,12 @@ ia64_mca_cpe_move_page(u64 paddr, u32 no
+ }
+ 
+ /*
+- * ia64_mca_cpe_migrate
+- *    The worker that does the actual migration.  It pulls a
+- *    physical address off the list and calls the migration code.
++ * cpe_process_queue
++ *    Pulls the physical address off the list and calls the migration code.
++ *    Will process all the addresses on the list.
+  */
+-static void
+-ia64_mca_cpe_migrate(struct work_struct *unused)
++void
++cpe_process_queue(void)
+ {
+       int ret;
+       u64 paddr;
+@@ -192,10 +196,36 @@ ia64_mca_cpe_migrate(struct work_struct 
+                       cpe_tail = 0;
+ 
+       } while (cpe_tail != cpe_head);
+-      work_scheduled = 0;
++      return;
++}
++
++inline int
++cpe_list_empty(void)
++{
++      return (cpe_head == cpe_tail) && (!cpe[cpe_head].paddr);
++}
++
++/*
++ * kthread_cpe_migrate
++ *    kthread_cpe_migrate is created at module load time and lives
++ *    until the module is removed.  When not active, it will sleep.
++ */
++static int
++kthread_cpe_migrate(void *ignore)
++{
++      while (cpe_active) {
++              /*
++               * wait for work
++               */
++              (void)wait_event_interruptible(cpe_activate_IRQ_wq,
++                                              (!cpe_list_empty() ||
++                                              !cpe_active));
++              cpe_process_queue();            /* process work */
++      }
++      complete(&kthread_cpe_migrated_exited);
++      return 0;
+ }
+ 
+-static DECLARE_WORK(cpe_enable_work, ia64_mca_cpe_migrate);
+ DEFINE_SPINLOCK(cpe_list_lock);
+ 
+ /*
+@@ -227,10 +257,7 @@ cpe_setup_migrate(void *rec)
+       if (ret < 0)
+               return -EINVAL;
+ 
+-      if ((cpe_head != cpe_tail) || (cpe[cpe_head].paddr != 0))
+-              /*
+-               * List not empty
+-               */
++      if (!cpe_list_empty())
+               for (i = 0; i < CE_HISTORY_LENGTH; i++) {
+                       if (PAGE_ALIGN(cpe[i].paddr) == PAGE_ALIGN(paddr)) {
+                               mstat_already_on_list++;
+@@ -255,10 +282,7 @@ cpe_setup_migrate(void *rec)
+       }
+       spin_unlock(&cpe_list_lock);
+ 
+-      if (!work_scheduled) {
+-              work_scheduled = 1;
+-              schedule_work(&cpe_enable_work);
+-      }
++      wake_up_interruptible(&cpe_activate_IRQ_wq);
+ 
+       return 1;
+ }
+@@ -395,12 +419,23 @@ static int __init
+ cpe_migrate_external_handler_init(void)
+ {
+       int error;
++      struct task_struct *kthread;
+ 
+       error = sysfs_create_file(kernel_kobj, &badram_attr.attr);
+       if (error)
+               return -EINVAL;
+ 
+       /*
++       * set up the kthread
++       */
++      cpe_active = 1;
++      kthread = kthread_run(kthread_cpe_migrate, NULL, "cpe_migrate");
++      if (IS_ERR(kthread)) {
++              complete(&kthread_cpe_migrated_exited);
++              return -EFAULT;
++      }
++
++      /*
+        * register external ce handler
+        */
+       if (ia64_reg_CE_extension(cpe_setup_migrate)) {
+@@ -418,6 +453,11 @@ cpe_migrate_external_handler_exit(void)
+ {
+       /* unregister external mca handlers */
+       ia64_unreg_CE_extension();
++
++      /* Stop kthread */
++      cpe_active = 0;                 /* tell kthread_cpe_migrate to exit */
++      wake_up_interruptible(&cpe_activate_IRQ_wq);
++      wait_for_completion(&kthread_cpe_migrated_exited);
+ 
+       sysfs_remove_file(kernel_kobj, &badram_attr.attr);
+ }
+