X-Git-Url: http://git.cascardo.info/?a=blobdiff_plain;f=include%2Fasm-generic%2Ftlb.h;h=25f01d0bc149cc388ce5a8e66d556669809e2b34;hb=53a59fc67f97374758e63a9c785891ec62324c81;hp=ed6642ad03e073fcd5a4d35d02ba9f6bcb5221b0;hpb=a458431e176ddb27e8ef8b98c2a681b217337393;p=cascardo%2Flinux.git

diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
index ed6642ad03e0..25f01d0bc149 100644
--- a/include/asm-generic/tlb.h
+++ b/include/asm-generic/tlb.h
@@ -78,6 +78,14 @@ struct mmu_gather_batch {
 #define MAX_GATHER_BATCH	\
 	((PAGE_SIZE - sizeof(struct mmu_gather_batch)) / sizeof(void *))
 
+/*
+ * Limit the maximum number of mmu_gather batches to reduce a risk of soft
+ * lockups for non-preemptible kernels on huge machines when a lot of memory
+ * is zapped during unmapping.
+ * 10K pages freed at once should be safe even without a preemption point.
+ */
+#define MAX_GATHER_BATCH_COUNT	(10000UL/MAX_GATHER_BATCH)
+
 /* struct mmu_gather is an opaque type used by the mm code for passing around
  * any data needed by arch specific code for tlb_remove_page.
  */
@@ -96,6 +104,7 @@ struct mmu_gather {
 	struct mmu_gather_batch *active;
 	struct mmu_gather_batch	local;
 	struct page		*__pages[MMU_GATHER_BUNDLE];
+	unsigned int		batch_count;
 };
 
 #define HAVE_GENERIC_MMU_GATHER