From: kirill@shutemov.name (Kirill A. Shutemov)
To: linux-riscv@lists.infradead.org
Subject: [PATCH 1/4] treewide: remove unused address argument from pte_alloc functions (v2)
Date: Thu, 25 Oct 2018 13:47:03 +0300 [thread overview]
Message-ID: <20181025104703.esl6wxyg2ihe4zoc@kshutemo-mobl1> (raw)
In-Reply-To: <20181024083716.GN3109@worktop.c.hoisthospitality.com>
On Wed, Oct 24, 2018 at 10:37:16AM +0200, Peter Zijlstra wrote:
> On Fri, Oct 12, 2018 at 06:31:57PM -0700, Joel Fernandes (Google) wrote:
> > This series speeds up mremap(2) syscall by copying page tables at the
> > PMD level even for non-THP systems. There is concern that the extra
> > 'address' argument that mremap passes to pte_alloc may do something
> > subtle architecture related in the future that may make the scheme not
> > work. Also we find that there is no point in passing the 'address' to
> > pte_alloc since its unused. So this patch therefore removes this
> > argument tree-wide resulting in a nice negative diff as well. Also
> > ensuring along the way that the enabled architectures do not do anything
> > funky with 'address' argument that goes unnoticed by the optimization.
>
> Did you happen to look at the history of where that address argument
> came from? -- just being curious here. ISTR something vague about
> architectures having different paging structure for different memory
> ranges.
I see some archicetures (i.e. sparc and, I believe power) used the address
for coloring. It's not needed anymore. Page allocator and SL?B are good
enough now.
See 3c936465249f ("[SPARC64]: Kill pgtable quicklists and use SLAB.")
--
Kirill A. Shutemov
WARNING: multiple messages have this Message-ID (diff)
From: "Kirill A. Shutemov" <kirill@shutemov.name>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-mips@linux-mips.org, Rich Felker <dalias@libc.org>,
linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org,
Catalin Marinas <catalin.marinas@arm.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Will Deacon <will.deacon@arm.com>,
Michal Hocko <mhocko@kernel.org>,
linux-mm@kvack.org, lokeshgidra@google.com,
"Joel Fernandes \(Google\)" <joel@joelfernandes.org>,
linux-riscv@lists.infradead.org, elfring@users.sourceforge.net,
Jonas Bonn <jonas@southpole.se>,
kvmarm@lists.cs.columbia.edu, dancol@google.com,
Yoshinori Sato <ysato@users.sourceforge.jp>,
sparclinux@vger.kernel.org, linux-xtensa@linux-xtensa.org,
linux-hexagon@vger.kernel.org, Helge Deller <deller@gmx.de>,
"maintainer:X86 ARCHITECTURE \(32-BIT AND 64-BIT\)"
<x86@kernel.org>,
hughd@google.com, "James E.J. Bottomley" <jejb@parisc-linux.org>,
kasan-dev@googlegroups.com, anton.ivanov@kot-begemot.co.uk,
Ingo Molnar <mingo@redhat.com>,
Geert Uytterhoeven <geert@linux-m68k.org>,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
linux-snps-arc@lists.infradead.org, kernel-team@android.com,
Sam Creasey <sammy@sammy.net>, Fenghua Yu <fenghua.yu@intel.com>,
linux-s390@vger.kernel.org, Jeff Dike <jdike@addtoit.com>,
linux-um@lists.infradead.org,
Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>,
Julia Lawall <Julia.Lawall@lip6.fr>,
linux-m68k@lists.linux-m68k.org, Borislav Petkov <bp@alien8.de>,
Andy Lutomirski <luto@kernel.org>,
nios2-dev@lists.rocketboards.org,
Stafford Horne <shorne@gmail.com>, Guan Xuetao <gxt@pku.edu.cn>,
Chris Zankel <chris@zankel.net>, Tony Luck <tony.luck@intel.com>,
Richard Weinberger <richard@nod.at>,
linux-parisc@vger.kernel.org, Max Filippov <jcmvbkbc@gmail.com>,
pantin@google.com, linux-kernel@vger.kernel.org,
minchan@kernel.org, Thomas Gleixner <tglx@linutronix.de>,
linux-alpha@vger.kernel.org, Ley Foon Tan <lftan@altera.com>,
akpm@linux-foundation.org, linuxppc-dev@lists.ozlabs.org,
"David S. Miller" <davem@davemloft.net>
Subject: Re: [PATCH 1/4] treewide: remove unused address argument from pte_alloc functions (v2)
Date: Thu, 25 Oct 2018 13:47:03 +0300 [thread overview]
Message-ID: <20181025104703.esl6wxyg2ihe4zoc@kshutemo-mobl1> (raw)
Message-ID: <20181025104703.HsxalDwn12Z0fHTKRWBj32oN9avRJStzS4Fm88vBZrA@z> (raw)
In-Reply-To: <20181024083716.GN3109@worktop.c.hoisthospitality.com>
On Wed, Oct 24, 2018 at 10:37:16AM +0200, Peter Zijlstra wrote:
> On Fri, Oct 12, 2018 at 06:31:57PM -0700, Joel Fernandes (Google) wrote:
> > This series speeds up mremap(2) syscall by copying page tables at the
> > PMD level even for non-THP systems. There is concern that the extra
> > 'address' argument that mremap passes to pte_alloc may do something
> > subtle architecture related in the future that may make the scheme not
> > work. Also we find that there is no point in passing the 'address' to
> > pte_alloc since its unused. So this patch therefore removes this
> > argument tree-wide resulting in a nice negative diff as well. Also
> > ensuring along the way that the enabled architectures do not do anything
> > funky with 'address' argument that goes unnoticed by the optimization.
>
> Did you happen to look at the history of where that address argument
> came from? -- just being curious here. ISTR something vague about
> architectures having different paging structure for different memory
> ranges.
I see some archicetures (i.e. sparc and, I believe power) used the address
for coloring. It's not needed anymore. Page allocator and SL?B are good
enough now.
See 3c936465249f ("[SPARC64]: Kill pgtable quicklists and use SLAB.")
--
Kirill A. Shutemov
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next prev parent reply other threads:[~2018-10-25 10:47 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-13 1:31 [PATCH 0/4] Add support for fast mremap Joel Fernandes (Google)
2018-10-13 1:31 ` Joel Fernandes (Google)
2018-10-13 1:31 ` [PATCH 1/4] treewide: remove unused address argument from pte_alloc functions (v2) Joel Fernandes (Google)
2018-10-13 1:31 ` Joel Fernandes (Google)
2018-10-24 8:37 ` Peter Zijlstra
2018-10-24 8:37 ` Peter Zijlstra
2018-10-25 2:21 ` Joel Fernandes
2018-10-25 2:21 ` Joel Fernandes
2018-10-26 8:52 ` Peter Zijlstra
2018-10-26 8:52 ` Peter Zijlstra
2018-10-25 10:47 ` Kirill A. Shutemov [this message]
2018-10-25 10:47 ` Kirill A. Shutemov
2018-10-26 8:50 ` Peter Zijlstra
2018-10-26 8:50 ` Peter Zijlstra
2018-10-13 1:31 ` [PATCH 2/4] mm: speed up mremap by 500x on large regions (v2) Joel Fernandes (Google)
2018-10-13 1:31 ` Joel Fernandes (Google)
2018-10-15 9:42 ` Christoph Hellwig
2018-10-15 9:42 ` Christoph Hellwig
2018-10-15 22:33 ` Joel Fernandes
2018-10-15 22:33 ` Joel Fernandes
2018-10-16 11:29 ` Vlastimil Babka
2018-10-16 11:29 ` Vlastimil Babka
2018-10-16 19:43 ` Joel Fernandes
2018-10-16 19:43 ` Joel Fernandes
2018-10-17 7:38 ` Vlastimil Babka
2018-10-17 7:38 ` Vlastimil Babka
2018-10-24 10:12 ` Kirill A. Shutemov
2018-10-24 10:12 ` Kirill A. Shutemov
2018-10-24 11:57 ` Balbir Singh
2018-10-24 11:57 ` Balbir Singh
2018-10-24 12:57 ` Kirill A. Shutemov
2018-10-24 12:57 ` Kirill A. Shutemov
2018-10-25 2:09 ` Joel Fernandes
2018-10-25 2:09 ` Joel Fernandes
2018-10-25 10:19 ` Kirill A. Shutemov
2018-10-25 10:19 ` Kirill A. Shutemov
2018-10-26 21:11 ` Joel Fernandes
2018-10-26 21:11 ` Joel Fernandes
2018-10-29 10:28 ` Will Deacon
2018-10-29 10:28 ` Will Deacon
2018-10-25 2:13 ` Joel Fernandes
2018-10-25 2:13 ` Joel Fernandes
2018-10-27 10:21 ` Balbir Singh
2018-10-27 10:21 ` Balbir Singh
2018-10-27 19:39 ` Joel Fernandes
2018-10-27 19:39 ` Joel Fernandes
2018-10-28 22:40 ` Balbir Singh
2018-10-28 22:40 ` Balbir Singh
2018-10-13 1:31 ` [PATCH 3/4] arm64: select HAVE_MOVE_PMD for faster mremap (v1) Joel Fernandes (Google)
2018-10-13 1:31 ` Joel Fernandes (Google)
2018-10-13 1:32 ` [PATCH 4/4] x86: " Joel Fernandes (Google)
2018-10-13 1:32 ` Joel Fernandes (Google)
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