All of lore.kernel.org
 help / color / mirror / Atom feed
From: Dave Hansen <dave@linux.vnet.ibm.com>
To: Peter Hurley <peter@hurleysoftware.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	Gleb Natapov <gleb@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
	x86@kernel.org, Marcelo Tosatti <mtosatti@redhat.com>,
	Rik van Riel <riel@redhat.com>
Subject: Re: [PATCH 0/5] [v3] fix illegal use of __pa() in KVM code
Date: Mon, 25 Feb 2013 06:42:22 -0800	[thread overview]
Message-ID: <512B784E.5070002@linux.vnet.ibm.com> (raw)
In-Reply-To: <1361741338.21499.38.camel@thor.lan>

On 02/24/2013 01:28 PM, Peter Hurley wrote:
> Now that the alloc_remap() has been/is being removed, is most/all of
> this being reverted?

I _believe_ alloc_remap() is the only case where we actually remapped
low memory.  However, there is still other code that does __pa()
translations for percpu areas: per_cpu_ptr_to_phys().  I _think_ it's
still theoretically possible to get some percpu data in the vmalloc() area.

> So in short, my questions are:
> 1) is the slow_virt_to_phys() necessary anymore?

kvm_vcpu_arch has a

        struct pvclock_vcpu_time_info hv_clock;

and I believe I mistook the two 'hv_clock's for each other.  However,
this doesn't hurt anything, and the performance difference is probably
horribly tiny.


WARNING: multiple messages have this Message-ID (diff)
From: Dave Hansen <dave@linux.vnet.ibm.com>
To: Peter Hurley <peter@hurleysoftware.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	Gleb Natapov <gleb@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
	x86@kernel.org, Marcelo Tosatti <mtosatti@redhat.com>,
	Rik van Riel <riel@redhat.com>
Subject: Re: [PATCH 0/5] [v3] fix illegal use of __pa() in KVM code
Date: Mon, 25 Feb 2013 06:42:22 -0800	[thread overview]
Message-ID: <512B784E.5070002@linux.vnet.ibm.com> (raw)
In-Reply-To: <1361741338.21499.38.camel@thor.lan>

On 02/24/2013 01:28 PM, Peter Hurley wrote:
> Now that the alloc_remap() has been/is being removed, is most/all of
> this being reverted?

I _believe_ alloc_remap() is the only case where we actually remapped
low memory.  However, there is still other code that does __pa()
translations for percpu areas: per_cpu_ptr_to_phys().  I _think_ it's
still theoretically possible to get some percpu data in the vmalloc() area.

> So in short, my questions are:
> 1) is the slow_virt_to_phys() necessary anymore?

kvm_vcpu_arch has a

        struct pvclock_vcpu_time_info hv_clock;

and I believe I mistook the two 'hv_clock's for each other.  However,
this doesn't hurt anything, and the performance difference is probably
horribly tiny.

--
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>

  parent reply	other threads:[~2013-02-25 14:58 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-22 21:24 [PATCH 0/5] [v3] fix illegal use of __pa() in KVM code Dave Hansen
2013-01-22 21:24 ` Dave Hansen
2013-01-22 21:24 ` [PATCH 1/5] make DEBUG_VIRTUAL work earlier in boot Dave Hansen
2013-01-22 21:24   ` Dave Hansen
2013-01-26  1:51   ` [tip:x86/mm] x86, mm: Make " tip-bot for Dave Hansen
2013-01-22 21:24 ` [PATCH 2/5] pagetable level size/shift/mask helpers Dave Hansen
2013-01-22 21:24   ` Dave Hansen
2013-01-26  1:52   ` [tip:x86/mm] x86, mm: Pagetable " tip-bot for Dave Hansen
2013-01-22 21:24 ` [PATCH 3/5] use new pagetable helpers in try_preserve_large_page() Dave Hansen
2013-01-22 21:24   ` Dave Hansen
2013-01-26  1:53   ` [tip:x86/mm] x86, mm: Use " tip-bot for Dave Hansen
2013-01-22 21:24 ` [PATCH 4/5] create slow_virt_to_phys() Dave Hansen
2013-01-22 21:24   ` Dave Hansen
2013-01-26  1:54   ` [tip:x86/mm] x86, mm: Create slow_virt_to_phys() tip-bot for Dave Hansen
2013-01-22 21:24 ` [PATCH 5/5] fix kvm's use of __pa() on percpu areas Dave Hansen
2013-01-22 21:24   ` Dave Hansen
2013-01-23  0:08   ` Marcelo Tosatti
2013-01-23  0:08     ` Marcelo Tosatti
2013-01-26  1:56   ` [tip:x86/mm] x86, kvm: Fix " tip-bot for Dave Hansen
2013-01-25 23:15 ` [PATCH 0/5] [v3] fix illegal use of __pa() in KVM code Dave Hansen
2013-01-25 23:15   ` Dave Hansen
2013-02-24 21:28 ` Peter Hurley
2013-02-24 21:28   ` Peter Hurley
2013-02-25  8:30   ` Gleb Natapov
2013-02-25  8:30     ` Gleb Natapov
2013-02-25 14:42   ` Dave Hansen [this message]
2013-02-25 14:42     ` Dave Hansen
2013-02-26 12:45     ` Peter Hurley
2013-02-26 12:45       ` Peter Hurley

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=512B784E.5070002@linux.vnet.ibm.com \
    --to=dave@linux.vnet.ibm.com \
    --cc=gleb@redhat.com \
    --cc=hpa@zytor.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mtosatti@redhat.com \
    --cc=peter@hurleysoftware.com \
    --cc=riel@redhat.com \
    --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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.