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.xen / xen-x86-exit-mmap

diff --git a/src/patches/suse-2.6.27.31/patches.xen/xen-x86-exit-mmap b/src/patches/suse-2.6.27.31/patches.xen/xen-x86-exit-mmap
new file mode 100644 (file)
index 0000000..30f302b
--- /dev/null
+++ b/src/patches/suse-2.6.27.31/patches.xen/xen-x86-exit-mmap
@@ -0,0 +1,67 @@
+Subject: be more aggressive about de-activating mm-s under destruction
+From: jbeulich@novell.com
+Patch-mainline: obsolete
+
+... by not only handling the current task on the CPU arch_exit_mmap()
+gets executed on, but also forcing remote CPUs to do so.
+
+Index: head-2008-12-01/arch/x86/mm/pgtable-xen.c
+===================================================================
+--- head-2008-12-01.orig/arch/x86/mm/pgtable-xen.c     2008-12-01 12:13:06.000000000 +0100
++++ head-2008-12-01/arch/x86/mm/pgtable-xen.c  2008-12-01 12:13:16.000000000 +0100
+@@ -418,27 +418,44 @@ void arch_dup_mmap(struct mm_struct *old
+               mm_pin(mm);
+ }
+ 
+-void arch_exit_mmap(struct mm_struct *mm)
++/*
++ * We aggressively remove defunct pgd from cr3. We execute unmap_vmas() *much*
++ * faster this way, as no hypercalls are needed for the page table updates.
++ */
++static void leave_active_mm(struct task_struct *tsk, struct mm_struct *mm)
++      __releases(tsk->alloc_lock)
+ {
+-      struct task_struct *tsk = current;
+-
+-      task_lock(tsk);
+-
+-      /*
+-       * We aggressively remove defunct pgd from cr3. We execute unmap_vmas()
+-       * *much* faster this way, as no tlb flushes means bigger wrpt batches.
+-       */
+       if (tsk->active_mm == mm) {
+               tsk->active_mm = &init_mm;
+               atomic_inc(&init_mm.mm_count);
+ 
+               switch_mm(mm, &init_mm, tsk);
+ 
+-              atomic_dec(&mm->mm_count);
+-              BUG_ON(atomic_read(&mm->mm_count) == 0);
++              if (atomic_dec_and_test(&mm->mm_count))
++                      BUG();
+       }
+ 
+       task_unlock(tsk);
++}
++
++static void _leave_active_mm(void *mm)
++{
++      struct task_struct *tsk = current;
++
++      if (spin_trylock(&tsk->alloc_lock))
++              leave_active_mm(tsk, mm);
++}
++
++void arch_exit_mmap(struct mm_struct *mm)
++{
++      struct task_struct *tsk = current;
++
++      task_lock(tsk);
++      leave_active_mm(tsk, mm);
++
++      preempt_disable();
++      smp_call_function_mask(mm->cpu_vm_mask, _leave_active_mm, mm, 1);
++      preempt_enable();
+ 
+       if (PagePinned(virt_to_page(mm->pgd))
+           && atomic_read(&mm->mm_count) == 1