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From: Dave Hansen <dave@sr71.net>
To: linux-kernel@vger.kernel.org
Cc: x86@kernel.org, linux-mm@kvack.org,
	torvalds@linux-foundation.org, akpm@linux-foundation.org,
	bp@alien8.de, ak@linux.intel.com, mhocko@suse.com,
	Dave Hansen <dave@sr71.net>,
	dave.hansen@linux.intel.com, minchan@kernel.org
Subject: [PATCH 4/6] mm: move flush in madvise_free_pte_range()
Date: Thu, 30 Jun 2016 17:12:15 -0700	[thread overview]
Message-ID: <20160701001215.C0689717@viggo.jf.intel.com> (raw)
In-Reply-To: <20160701001209.7DA24D1C@viggo.jf.intel.com>


From: Dave Hansen <dave.hansen@linux.intel.com>

I think this code is OK and does not *need* to be patched.  We
are just rewriting the PTE without the Accessed and Dirty bits.
The hardware could come along and set them at any time with or
without the erratum that this series addresses

But this does make the ptep_get_and_clear_full() and
tlb_remove_tlb_entry() calls here more consistent with the other
places they are used together and look *obviously* the same
between call-sites.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Minchan Kim <minchan@kernel.org>
---

 b/mm/madvise.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff -puN mm/madvise.c~knl-leak-40-madvise_free_pte_range-move-flush mm/madvise.c
--- a/mm/madvise.c~knl-leak-40-madvise_free_pte_range-move-flush	2016-06-30 17:10:42.557246755 -0700
+++ b/mm/madvise.c	2016-06-30 17:10:42.561246936 -0700
@@ -369,13 +369,13 @@ static int madvise_free_pte_range(pmd_t
 			 */
 			ptent = ptep_get_and_clear_full(mm, addr, pte,
 							tlb->fullmm);
+			tlb_remove_tlb_entry(tlb, pte, addr);
 
 			ptent = pte_mkold(ptent);
 			ptent = pte_mkclean(ptent);
 			set_pte_at(mm, addr, pte, ptent);
 			if (PageActive(page))
 				deactivate_page(page);
-			tlb_remove_tlb_entry(tlb, pte, addr);
 		}
 	}
 out:
_

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  parent reply	other threads:[~2016-07-01  0:12 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-01  0:12 [PATCH 0/6] [v3] Workaround for Xeon Phi PTE A/D bits erratum Dave Hansen
2016-07-01  0:12 ` [PATCH 1/6] x86: fix duplicated X86_BUG(9) macro Dave Hansen
2016-07-01  9:23   ` Borislav Petkov
2016-07-01 16:30     ` Andy Lutomirski
2016-07-01 16:46       ` Borislav Petkov
2016-07-03 14:36         ` Andy Lutomirski
2016-07-03 18:44           ` Borislav Petkov
2016-07-01  0:12 ` [PATCH 2/6] mm, tlb: add mmu_gather->saw_unset_a_or_d Dave Hansen
2016-07-01  0:12 ` [PATCH 3/6] mm: add force_batch_flush to mmu_gather Dave Hansen
2016-07-01  0:12 ` Dave Hansen [this message]
2016-07-01  0:12 ` [PATCH 5/6] mm: make tlb_flush_mmu_tlbonly() return whether it flushed Dave Hansen
2016-07-01  0:12 ` [PATCH 6/6] x86: Fix stray A/D bit setting into non-present PTEs Dave Hansen
2016-07-01  1:50   ` Nadav Amit
2016-07-01  1:54     ` Dave Hansen
2016-07-01  2:55   ` Linus Torvalds
2016-07-01  3:06     ` Brian Gerst
2016-07-01  3:21       ` Linus Torvalds
2016-07-03 17:10       ` Dave Hansen
2016-07-01  4:39     ` Dave Hansen
2016-07-01  5:43       ` Linus Torvalds
2016-07-01 14:25         ` Eric W. Biederman
2016-07-01 15:51           ` Dave Hansen
2016-07-01 18:12             ` Eric W. Biederman
2016-07-01 16:07       ` Linus Torvalds
2016-07-01 16:14         ` Dave Hansen
2016-07-01 16:25           ` Linus Torvalds
     [not found] <016001d1d36e$ef1db5a0$cd5920e0$@alibaba-inc.com>
2016-07-01  8:30 ` [PATCH 4/6] mm: move flush in madvise_free_pte_range() Hillf Danton

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