From mboxrd@z Thu Jan  1 00:00:00 1970
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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, Vineet Gupta <vgupta@synopsys.com>,
	Mel Gorman <mgorman@suse.de>, Hugh Dickins <hughd@google.com>,
	Rik van Riel <riel@redhat.com>,
	David Rientjes <rientjes@google.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Max Filippov <jcmvbkbc@gmail.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Linus Torvalds <torvalds@linux-foundation.org>
Subject: [ 01/99] mm: fix the TLB range flushed when __tlb_remove_page() runs out of slots
Date: Fri,  2 Aug 2013 18:07:14 +0800
Message-Id: <20130802100225.679129589@linuxfoundation.org>
In-Reply-To: <20130802100225.478715166@linuxfoundation.org>
References: <20130802100225.478715166@linuxfoundation.org>
Sender: linux-kernel-owner@vger.kernel.org
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3.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Vineet Gupta <Vineet.Gupta1@synopsys.com>

commit e6c495a96ce02574e765d5140039a64c8d4e8c9e upstream.

zap_pte_range loops from @addr to @end.  In the middle, if it runs out of
batching slots, TLB entries needs to be flushed for @start to @interim,
NOT @interim to @end.

Since ARC port doesn't use page free batching I can't test it myself but
this seems like the right thing to do.

Observed this when working on a fix for the issue at thread:
http://www.spinics.net/lists/linux-arch/msg21736.html

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 mm/memory.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1101,6 +1101,7 @@ static unsigned long zap_pte_range(struc
 	spinlock_t *ptl;
 	pte_t *start_pte;
 	pte_t *pte;
+	unsigned long range_start = addr;
 
 again:
 	init_rss_vec(rss);
@@ -1206,12 +1207,14 @@ again:
 		force_flush = 0;
 
 #ifdef HAVE_GENERIC_MMU_GATHER
-		tlb->start = addr;
-		tlb->end = end;
+		tlb->start = range_start;
+		tlb->end = addr;
 #endif
 		tlb_flush_mmu(tlb);
-		if (addr != end)
+		if (addr != end) {
+			range_start = addr;
 			goto again;
+		}
 	}
 
 	return addr;