linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Linus Torvalds <torvalds@linux-foundation.org>
To: Aaron Lu <aaron.lu@intel.com>
Cc: Linux Memory Management List <linux-mm@kvack.org>,
	Dave Hansen <dave.hansen@intel.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
	Huang Ying <ying.huang@intel.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] mremap: move_ptes: check pte dirty after its removal
Date: Mon, 28 Nov 2016 19:06:39 -0800	[thread overview]
Message-ID: <CA+55aFx_vOfab=WNHd=OR7vng2V_UqrEdx_xZBsKv_ohE65f8w@mail.gmail.com> (raw)
In-Reply-To: <977b6c8b-2df3-5f4b-0d6c-fe766cf3fae0@intel.com>

On Mon, Nov 28, 2016 at 6:57 PM, Aaron Lu <aaron.lu@intel.com> wrote:
>
> Here is a fix patch, sorry for the trouble.

I don't think you tested this one.. You've now essentially reverted
5d1904204c99 entirely by making the new force_flush logic a no-op.

> +               pmd = pmdp_huge_get_and_clear(mm, old_addr, old_pmd);
>                 if (pmd_present(*old_pmd) && pmd_dirty(*old_pmd))
>                         force_flush = true;

You need to be testing "pmd", not "*old_pmd".

Because now "*old_pmd" will be zeroes.

>                 if (pte_present(*old_pte) && pte_dirty(*old_pte))
>                         force_flush = true;

Similarly here. You need to check "pte", not "*old_pte".

            Linus

  reply	other threads:[~2016-11-29  3:07 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <026b73f6-ca1d-e7bb-766c-4aaeb7071ce6@intel.com>
2016-11-17  7:45 ` [PATCH] mremap: fix race between mremap() and page cleanning Aaron Lu
     [not found] ` <CA+55aFzHfpZckv8ck19fZSFK+3TmR5eF=BsDzhwVGKrbyEBjEw@mail.gmail.com>
     [not found]   ` <c160bc18-7c1b-2d54-8af1-7c5bfcbcefe8@intel.com>
2016-11-28  8:37     ` [PATCH 0/2] use mmu gather logic for tlb flush in mremap Aaron Lu
2016-11-28  8:39       ` [PATCH 1/2] tlb: export tlb_flush_mmu_tlbonly Aaron Lu
2016-11-28  8:40       ` [PATCH 2/2] mremap: use mmu gather logic for tlb flush in mremap Aaron Lu
2016-11-28 17:15         ` Linus Torvalds
2016-11-29  2:57           ` [PATCH] mremap: move_ptes: check pte dirty after its removal Aaron Lu
2016-11-29  3:06             ` Linus Torvalds [this message]
2016-11-29  3:22               ` Aaron Lu
2016-11-29  5:27               ` [PATCH update] " Aaron Lu
2016-11-28 17:32         ` [PATCH 2/2] mremap: use mmu gather logic for tlb flush in mremap Dave Hansen
2016-11-28 17:42           ` Linus Torvalds

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CA+55aFx_vOfab=WNHd=OR7vng2V_UqrEdx_xZBsKv_ohE65f8w@mail.gmail.com' \
    --to=torvalds@linux-foundation.org \
    --cc=aaron.lu@intel.com \
    --cc=akpm@linux-foundation.org \
    --cc=dave.hansen@intel.com \
    --cc=kirill.shutemov@linux.intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=ying.huang@intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).