[PATCH 2/5] mm, notifier: Prime lockdep

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



We want to teach lockdep that mmu notifiers can be called from direct
reclaim paths, since on many CI systems load might never reach that
level (e.g. when just running fuzzer or small functional tests).

Motivated by a discussion with Jason.

I've put the annotation into mmu_notifier_register since only when we
have mmu notifiers registered is there any point in teaching lockdep
about them. Also, we already have a kmalloc(, GFP_KERNEL), so this is
safe.

Cc: Jason Gunthorpe <jgg@xxxxxxxx>
Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: "Jérôme Glisse" <jglisse@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: "Christian König" <christian.koenig@xxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx>
---
 mm/mmu_notifier.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c
index d48d3b2abd68..0523555933c9 100644
--- a/mm/mmu_notifier.c
+++ b/mm/mmu_notifier.c
@@ -259,6 +259,13 @@ int __mmu_notifier_register(struct mmu_notifier *mn, struct mm_struct *mm)
 	lockdep_assert_held_write(&mm->mmap_sem);
 	BUG_ON(atomic_read(&mm->mm_users) <= 0);
 
+	if (IS_ENABLED(CONFIG_LOCKDEP)) {
+		fs_reclaim_acquire(GFP_KERNEL);
+		lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
+		lock_map_release(&__mmu_notifier_invalidate_range_start_map);
+		fs_reclaim_release(GFP_KERNEL);
+	}
+
 	mn->mm = mm;
 	mn->users = 1;
 
-- 
2.23.0

_______________________________________________
dri-devel mailing list
dri-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/dri-devel




[Index of Archives]     [Linux DRI Users]     [Linux Intel Graphics]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux