From: "Yang, Bin" <bin.yang@intel.com>
To: "tglx@linutronix.de" <tglx@linutronix.de>
Cc: "mingo@kernel.org" <mingo@kernel.org>,
"hpa@zytor.com" <hpa@zytor.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"peterz@infradead.org" <peterz@infradead.org>,
"x86@kernel.org" <x86@kernel.org>
Subject: Re: [PATCH] x86/mm: fix cpu stuck issue in __change_page_attr_set_clr
Date: Wed, 4 Jul 2018 10:15:45 +0000 [thread overview]
Message-ID: <34a76fad5c43c11ce8ceb491537b453d8053bdb2.camel@intel.com> (raw)
In-Reply-To: <alpine.DEB.2.21.1807041119260.1816@nanos.tec.linutronix.de>
e820 table:
=================
[ 0.000000] BIOS-e820: [mem 0x0000000000000000-0x000000000009fbff]
usable
[ 0.000000] BIOS-e820: [mem 0x000000000009fc00-0x000000000009ffff]
reserved
[ 0.000000] BIOS-e820: [mem 0x00000000000f0000-0x00000000000fffff]
reserved
[ 0.000000] BIOS-e820: [mem 0x0000000000100000-0x00000000bffdffff]
usable
[ 0.000000] BIOS-e820: [mem 0x00000000bffe0000-0x00000000bfffffff]
reserved
[ 0.000000] BIOS-e820: [mem 0x00000000feffc000-0x00000000feffffff]
reserved
[ 0.000000] BIOS-e820: [mem 0x00000000fffc0000-0x00000000ffffffff]
reserved
[ 0.000000] BIOS-e820: [mem 0x0000000100000000-0x000000013fffffff]
usable
call chain:
======================
...
=> free_init_pages(what="initrd" or "unused kernel",
begin=ffff9b26b....000, end=ffff9b26c....000); begin and end addresses
are random. The begin/end value above is just for reference.
=> set_memory_rw()
=> change_page_attr_set()
=> change_page_attr_set_clr()
=> __change_page_attr_set_clr(); cpa->numpages is 512 on my board if
what=="unused kernel"
=> __change_page_attr()
=> try_preserve_large_page(); address=ffff9b26bfacf000, pfn=80000,
level=3; and the check loop count is 262144, exit loop after 861 usecs
on my board
the actual problem
===================
sometimes, free_init_pages returns after hundreds of secounds. The
major impact is kernel boot time.
On Wed, 2018-07-04 at 11:20 +0200, Thomas Gleixner wrote:
> On Wed, 4 Jul 2018, Yang, Bin wrote:
>
> > You are completely right. After considering, I think my patch is
> > like a
> > workaround but not real fix. I am trying to re-write a new patch
> > without cache implementation.
>
> Care to explain the actual problem coherently _before_ writing yet
> another
> patch?
>
> Thanks,
>
> tglx
next prev parent reply other threads:[~2018-07-04 10:15 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-28 10:05 [PATCH] x86/mm: fix cpu stuck issue in __change_page_attr_set_clr Bin Yang
2018-07-03 13:57 ` Thomas Gleixner
2018-07-04 6:07 ` Yang, Bin
2018-07-04 7:40 ` Thomas Gleixner
2018-07-04 9:16 ` Yang, Bin
2018-07-04 9:20 ` Thomas Gleixner
2018-07-04 10:15 ` Yang, Bin [this message]
2018-07-04 14:01 ` Thomas Gleixner
2018-07-05 1:08 ` Yang, Bin
2018-07-05 5:30 ` Thomas Gleixner
2018-07-05 5:48 ` Yang, Bin
2018-07-05 6:15 ` Thomas Gleixner
2018-07-10 2:18 ` Yang, Bin
2018-07-16 7:48 ` Thomas Gleixner
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=34a76fad5c43c11ce8ceb491537b453d8053bdb2.camel@intel.com \
--to=bin.yang@intel.com \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=x86@kernel.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).