From: Minchan Kim <minchan@kernel.org>
To: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, Jason Evans <je@fb.com>,
"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
Will Deacon <will.deacon@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
"[4.5+]" <stable@vger.kernel.org>,
Andreas Schwab <schwab@suse.de>
Subject: Re: [PATCH] mm: pmd dirty emulation in page fault handler
Date: Thu, 22 Dec 2016 23:52:03 +0900 [thread overview]
Message-ID: <20161222145203.GA18970@bbox> (raw)
In-Reply-To: <20161222081713.GA32480@node.shutemov.name>
Hello,
On Thu, Dec 22, 2016 at 11:17:13AM +0300, Kirill A. Shutemov wrote:
< snip >
> > diff --git a/mm/memory.c b/mm/memory.c
> > index 36c774f..7408ddc 100644
> > --- a/mm/memory.c
> > +++ b/mm/memory.c
> > @@ -3637,18 +3637,20 @@ static int __handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
> > if (pmd_protnone(orig_pmd) && vma_is_accessible(vma))
> > return do_huge_pmd_numa_page(&vmf, orig_pmd);
> >
> > - if ((vmf.flags & FAULT_FLAG_WRITE) &&
> > - !pmd_write(orig_pmd)) {
> > - ret = wp_huge_pmd(&vmf, orig_pmd);
> > - if (!(ret & VM_FAULT_FALLBACK))
> > + if (vmf.flags & FAULT_FLAG_WRITE) {
> > + if (!pmd_write(orig_pmd)) {
> > + ret = wp_huge_pmd(&vmf, orig_pmd);
> > + if (ret == VM_FAULT_FALLBACK)
>
> In theory, more than one flag can be set and it would lead to
> false-negative. Bit check was the right thing.
>
> And I don't understand why do you need to change code in
> __handle_mm_fault() at all.
> From what I see change to huge_pmd_set_accessed() should be enough.
Yeb. Thanks for the review. Here v2 goes.
next prev parent reply other threads:[~2016-12-22 14:52 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-21 23:48 [PATCH] mm: pmd dirty emulation in page fault handler Minchan Kim
2016-12-22 8:17 ` Kirill A. Shutemov
2016-12-22 14:52 ` Minchan Kim [this message]
2016-12-22 18:35 ` Kirill A. Shutemov
2016-12-22 22:12 ` Andreas Schwab
2016-12-23 9:17 ` Michal Hocko
2016-12-23 9:53 ` Minchan Kim
2016-12-23 11:54 ` Michal Hocko
2016-12-23 14:01 ` Minchan Kim
2016-12-23 14:53 ` Michal Hocko
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=20161222145203.GA18970@bbox \
--to=minchan@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=catalin.marinas@arm.com \
--cc=je@fb.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=kirill@shutemov.name \
--cc=linux-arch@vger.kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-mm@kvack.org \
--cc=schwab@suse.de \
--cc=stable@vger.kernel.org \
--cc=will.deacon@arm.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).