From: Peter Zijlstra <peterz@infradead.org>
To: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
linux-mm@kvack.org, Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@elte.hu>,
akpm@linux-foundation.org, Rik van Riel <riel@redhat.com>,
Hugh Dickins <hugh.dickins@tiscali.co.uk>,
Mel Gorman <mel@csn.ul.ie>, Nick Piggin <npiggin@kernel.dk>,
Alex Shi <alex.shi@intel.com>,
"Nikunj A. Dadhania" <nikunj@linux.vnet.ibm.com>,
Konrad Rzeszutek Wilk <konrad@darnok.org>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
David Miller <davem@davemloft.net>,
Russell King <rmk@arm.linux.org.uk>,
Catalin Marinas <catalin.marinas@arm.com>,
Chris Metcalf <cmetcalf@tilera.com>,
Tony Luck <tony.luck@intel.com>, Paul Mundt <lethal@linux-sh.org>,
Jeff Dike <jdike@addtoit.com>,
Richard Weinberger <richard@nod.at>,
Ralf Baechle <ralf@linux-mips.org>,
Kyle McMartin <kyle@mcmartin.ca>,
James Bottomley <jejb@parisc-linux.org>,
Chris Zankel <chris@zankel.net>
Subject: Re: [PATCH 08/20] mm: Optimize fullmm TLB flushing
Date: Thu, 28 Jun 2012 13:30:48 +0200 [thread overview]
Message-ID: <1340883048.28750.25.camel@twins> (raw)
In-Reply-To: <20120628131950.0afe39f0@de.ibm.com>
On Thu, 2012-06-28 at 13:19 +0200, Martin Schwidefsky wrote:
> The cpu can create speculative TLB entries, but only if it runs in the
> mode that uses the respective mm. We have two mm's active at the same
> time, the kernel mm (init_mm) and the user mm. While the cpu runs only
> in kernel mode it is not allowed to create TLBs for the user mm.
> While running in user mode it is allowed to speculatively create TLBs.
OK, that's neat.
> Basically we have two special requirements on s390:
> 1) do not modify ptes while attached to another cpu except with the
> special IPTE / IDTE instructions
Right, and your fullmm case works by doing a global invalidate after all
threads have ceased userspace execution, this allows you to do away with
the IPTE/IDTE instructions since there's no other active cpus on the
userspace mm anymore.
> 2) do a TLB flush before freeing any kind of page table page, s390
> needs a flush for pud, pmd & pte tables.
Right, we do that (now)..
prev parent reply other threads:[~2012-06-28 11:31 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20120627211540.459910855@chello.nl>
[not found] ` <20120627212830.693232452@chello.nl>
[not found] ` <CA+55aFwa41fzvx8EZG_gODvw7hSpr+iP+w5fXp6jUcQh-4nFgQ@mail.gmail.com>
2012-06-27 23:01 ` [PATCH 02/20] mm: Add optional TLB flush to generic RCU page-table freeing Peter Zijlstra
2012-06-27 23:42 ` Linus Torvalds
2012-06-28 7:09 ` Benjamin Herrenschmidt
2012-06-28 11:05 ` Peter Zijlstra
2012-06-28 12:00 ` Benjamin Herrenschmidt
2012-07-24 5:12 ` Nikunj A Dadhania
[not found] ` <20120627212831.137126018@chello.nl>
[not found] ` <CA+55aFwZoVK76ue7tFveV0XZpPUmoCVXJx8550OxPm+XKCSSZA@mail.gmail.com>
[not found] ` <1340838154.10063.86.camel@twins>
2012-06-27 23:13 ` [PATCH 08/20] mm: Optimize fullmm TLB flushing Peter Zijlstra
2012-06-27 23:23 ` Linus Torvalds
2012-06-27 23:33 ` Linus Torvalds
2012-06-28 10:55 ` Peter Zijlstra
2012-06-28 11:19 ` Martin Schwidefsky
2012-06-28 11:30 ` Peter Zijlstra [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=1340883048.28750.25.camel@twins \
--to=peterz@infradead.org \
--cc=akpm@linux-foundation.org \
--cc=alex.shi@intel.com \
--cc=benh@kernel.crashing.org \
--cc=catalin.marinas@arm.com \
--cc=chris@zankel.net \
--cc=cmetcalf@tilera.com \
--cc=davem@davemloft.net \
--cc=hugh.dickins@tiscali.co.uk \
--cc=jdike@addtoit.com \
--cc=jejb@parisc-linux.org \
--cc=konrad@darnok.org \
--cc=kyle@mcmartin.ca \
--cc=lethal@linux-sh.org \
--cc=linux-arch@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mel@csn.ul.ie \
--cc=mingo@elte.hu \
--cc=nikunj@linux.vnet.ibm.com \
--cc=npiggin@kernel.dk \
--cc=ralf@linux-mips.org \
--cc=richard@nod.at \
--cc=riel@redhat.com \
--cc=rmk@arm.linux.org.uk \
--cc=schwidefsky@de.ibm.com \
--cc=tglx@linutronix.de \
--cc=tony.luck@intel.com \
--cc=torvalds@linux-foundation.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