[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <ZFs0k2rrLPH9A/UU@casper.infradead.org>
Date: Wed, 10 May 2023 07:07:15 +0100
From: Matthew Wilcox <willy@...radead.org>
To: Hugh Dickins <hughd@...gle.com>
Cc: Andrew Morton <akpm@...ux-foundation.org>,
Mike Kravetz <mike.kravetz@...cle.com>,
Mike Rapoport <rppt@...nel.org>,
"Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
David Hildenbrand <david@...hat.com>,
Suren Baghdasaryan <surenb@...gle.com>,
Qi Zheng <zhengqi.arch@...edance.com>,
Russell King <linux@...linux.org.uk>,
Catalin Marinas <catalin.marinas@....com>,
Will Deacon <will@...nel.org>,
Geert Uytterhoeven <geert@...ux-m68k.org>,
Greg Ungerer <gerg@...ux-m68k.org>,
Michal Simek <monstr@...str.eu>,
Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
Helge Deller <deller@....de>,
John David Anglin <dave.anglin@...l.net>,
"Aneesh Kumar K.V" <aneesh.kumar@...ux.ibm.com>,
Michael Ellerman <mpe@...erman.id.au>,
Alexandre Ghiti <alexghiti@...osinc.com>,
Palmer Dabbelt <palmer@...belt.com>,
Heiko Carstens <hca@...ux.ibm.com>,
Christian Borntraeger <borntraeger@...ux.ibm.com>,
Claudio Imbrenda <imbrenda@...ux.ibm.com>,
John Paul Adrian Glaubitz <glaubitz@...sik.fu-berlin.de>,
"David S. Miller" <davem@...emloft.net>,
Chris Zankel <chris@...kel.net>,
Max Filippov <jcmvbkbc@...il.com>, x86@...nel.org,
linux-arm-kernel@...ts.infradead.org, linux-ia64@...r.kernel.org,
linux-m68k@...ts.linux-m68k.org, linux-mips@...r.kernel.org,
linux-parisc@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
linux-riscv@...ts.infradead.org, linux-s390@...r.kernel.org,
linux-sh@...r.kernel.org, sparclinux@...r.kernel.org,
linux-kernel@...r.kernel.org, linux-mm@...ck.org
Subject: Re: [PATCH 00/23] arch: allow pte_offset_map[_lock]() to fail
On Tue, May 09, 2023 at 09:39:13PM -0700, Hugh Dickins wrote:
> Two: pte_offset_map() will need to do an rcu_read_lock(), with the
> corresponding rcu_read_unlock() in pte_unmap(). But most architectures
> never supported CONFIG_HIGHPTE, so some don't always call pte_unmap()
> after pte_offset_map(), or have used userspace pte_offset_map() where
> pte_offset_kernel() is more correct. No problem in the current tree,
> but a problem once an rcu_read_unlock() will be needed to keep balance.
Hi Hugh,
I shall have to spend some time looking at these patches, but at LSFMM
just a few hours ago, I proposed and nobody objected to removing
CONFIG_HIGHPTE. I don't intend to take action on that consensus
immediately, so I can certainly wait until your patches are applied, but
if this information simplifies what you're doing, feel free to act on it.
Powered by blists - more mailing lists