From: Cyrill Gorcunov <gorcunov@gmail.com>
To: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [rfc 0/3] Cleaning up soft-dirty bit usage
Date: Mon, 7 Apr 2014 17:24:37 +0400 [thread overview]
Message-ID: <20140407132437.GH1444@moon> (raw)
In-Reply-To: <20140407130701.GA16677@node.dhcp.inet.fi>
On Mon, Apr 07, 2014 at 04:07:01PM +0300, Kirill A. Shutemov wrote:
> On Thu, Apr 03, 2014 at 10:48:44PM +0400, Cyrill Gorcunov wrote:
> > Hi! I've been trying to clean up soft-dirty bit usage. I can't cleanup
> > "ridiculous macros in pgtable-2level.h" completely because I need to
> > define _PAGE_FILE,_PAGE_PROTNONE,_PAGE_NUMA bits in sequence manner
> > like
> >
> > #define _PAGE_BIT_FILE (_PAGE_BIT_PRESENT + 1) /* _PAGE_BIT_RW */
> > #define _PAGE_BIT_NUMA (_PAGE_BIT_PRESENT + 2) /* _PAGE_BIT_USER */
> > #define _PAGE_BIT_PROTNONE (_PAGE_BIT_PRESENT + 3) /* _PAGE_BIT_PWT */
> >
> > which can't be done right now because numa code needs to save original
> > pte bits for example in __split_huge_page_map, if I'm not missing something
> > obvious.
>
> Sorry, I didn't get this. How __split_huge_page_map() does depend on pte
> bits order?
__split_huge_page_map
...
for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) {
...
here we modify with pte bits
entry = pte_mknuma(entry); --> clean _PAGE_PRESENT and set _PAGE_NUMA
pte bits must remain valid and meaningful, for example we might
have set _PAGE_RW here
> > is it intentional, and @prot_numa argument is supposed to be passed
> > with prot_numa = 1 one day, or it's leftover from old times?
>
> I see one more user of change_protection() -- change_prot_numa(), which
> has .prot_numa == 1.
Yeah, thanks, managed to miss this.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
prev parent reply other threads:[~2014-04-07 13:24 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-03 18:48 [rfc 0/3] Cleaning up soft-dirty bit usage Cyrill Gorcunov
2014-04-03 18:48 ` [rfc 1/3] mm: pgtable -- Drop unneeded preprocessor ifdef Cyrill Gorcunov
2014-04-03 18:48 ` [rfc 2/3] mm: pgtable -- Require X86_64 for soft-dirty tracker Cyrill Gorcunov
2014-04-03 18:48 ` [rfc 3/3] mm: pgtable -- Use _PAGE_SOFT_DIRTY for swap entries Cyrill Gorcunov
2014-04-07 13:07 ` [rfc 0/3] Cleaning up soft-dirty bit usage Kirill A. Shutemov
2014-04-07 13:24 ` Cyrill Gorcunov [this message]
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=20140407132437.GH1444@moon \
--to=gorcunov@gmail.com \
--cc=kirill@shutemov.name \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
/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).