From: Dave Hansen <dave.hansen@intel.com>
To: Song Liu <songliubraving@fb.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linux MM <linux-mm@kvack.org>, Kernel Team <Kernel-team@fb.com>,
"stable@vger.kernel.org" <stable@vger.kernel.org>,
Joerg Roedel <jroedel@suse.de>,
Thomas Gleixner <tglx@linutronix.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH] x86/mm/pti: in pti_clone_pgtable() don't increase addr by PUD_SIZE
Date: Tue, 20 Aug 2019 07:18:06 -0700 [thread overview]
Message-ID: <463379e3-5a31-5064-dd02-ea2fe149fa7e@intel.com> (raw)
In-Reply-To: <520249E9-1784-4728-88D7-5A21DFE17B8E@fb.com>
On 8/20/19 7:14 AM, Song Liu wrote:
>> *But*, that shouldn't get hit on a Skylake CPU since those have PCIDs
>> and shouldn't have a global kernel image. Could you confirm whether
>> PCIDs are supported on this CPU?
> Yes, pcid is listed in /proc/cpuinfo.
So what's going on? Could you confirm exactly which pti_clone_pgtable()
is causing you problems? Do you have a theory as to why this manifests
as a performance problem rather than a functional one?
A diff of these:
/sys/kernel/debug/page_tables/current_user
/sys/kernel/debug/page_tables/current_kernel
before and after your patch might be helpful.
next prev parent reply other threads:[~2019-08-20 14:18 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-20 7:51 Song Liu
2019-08-20 9:12 ` Thomas Gleixner
2019-08-20 13:17 ` Song Liu
2019-08-20 10:00 ` Peter Zijlstra
2019-08-20 11:16 ` Thomas Gleixner
2019-08-20 13:21 ` Song Liu
2019-08-20 13:39 ` Thomas Gleixner
2019-08-20 13:55 ` Rik van Riel
2019-08-20 14:00 ` Song Liu
2019-08-20 16:56 ` [PATCH v2] " Rik van Riel
2019-08-20 13:21 ` [PATCH] " Rik van Riel
2019-08-20 13:19 ` Song Liu
2019-08-20 13:57 ` Dave Hansen
2019-08-20 14:14 ` Song Liu
2019-08-20 14:18 ` Dave Hansen [this message]
2019-08-20 16:05 ` Song Liu
2019-08-20 16:38 ` Song Liu
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=463379e3-5a31-5064-dd02-ea2fe149fa7e@intel.com \
--to=dave.hansen@intel.com \
--cc=Kernel-team@fb.com \
--cc=dave.hansen@linux.intel.com \
--cc=jroedel@suse.de \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=luto@kernel.org \
--cc=peterz@infradead.org \
--cc=songliubraving@fb.com \
--cc=stable@vger.kernel.org \
--cc=tglx@linutronix.de \
/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