From: Al Viro <viro@zeniv.linux.org.uk>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Vineet Gupta <Vineet.Gupta1@synopsys.com>,
Khalid Aziz <khalid.aziz@oracle.com>,
Andrey Konovalov <andreyknvl@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Peter Zijlstra <peterz@infradead.org>,
Christian Brauner <christian.brauner@ubuntu.com>,
Kees Cook <keescook@chromium.org>, Ingo Molnar <mingo@kernel.org>,
Aleksa Sarai <cyphar@cyphar.com>,
"open list:SYNOPSYS ARC ARCHITECTURE"
<linux-snps-arc@lists.infradead.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-arch <linux-arch@vger.kernel.org>
Subject: Re: [RFC 1/4] asm-generic/uaccess: don't define inline functions if noinline lib/* in use
Date: Wed, 15 Jan 2020 14:12:24 +0000 [thread overview]
Message-ID: <20200115141224.GH8904@ZenIV.linux.org.uk> (raw)
In-Reply-To: <CAK8P3a2ao=xBuy3XHBkdo03KEjpMHGe9ahwj-uogtkZBXsMkGw@mail.gmail.com>
On Wed, Jan 15, 2020 at 10:08:31AM +0100, Arnd Bergmann wrote:
> > I would suggest that anybody who uses asm-generic/uaccess.h needs to
> > simply use the generic library version.
>
> Or possibly just everybody altogether: the remaining architectures that
> have a custom implementation don't seem to be doing any better either.
No go for s390. There you really want to access userland memory in
larger chunks - it's oriented for block transfers. IIRC, the insn
they are using has a costly setup phase, independent of the amount
to copy, followed by reasonably fast transfer more or less linear
by the size.
next prev parent reply other threads:[~2020-01-15 14:12 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-14 20:08 [RFC 0/4] Switching ARC to optimized generic strncpy_from_user Vineet Gupta
2020-01-14 20:08 ` [RFC 1/4] asm-generic/uaccess: don't define inline functions if noinline lib/* in use Vineet Gupta
2020-01-14 20:57 ` Arnd Bergmann
2020-01-15 23:01 ` Vineet Gupta
2020-01-16 11:43 ` Arnd Bergmann
2020-01-14 21:32 ` Linus Torvalds
2020-01-15 9:08 ` Arnd Bergmann
2020-01-15 14:12 ` Al Viro [this message]
2020-01-15 14:21 ` Arnd Bergmann
2020-01-14 20:08 ` [RFC 2/4] lib/strncpy_from_user: Remove redundant user space pointer range check Vineet Gupta
2020-01-14 21:22 ` Linus Torvalds
2020-01-14 21:52 ` Vineet Gupta
2020-01-14 23:46 ` Al Viro
2020-01-15 14:42 ` Andrey Konovalov
2020-01-15 23:00 ` Vineet Gupta
2020-01-14 20:08 ` [RFC 3/4] ARC: uaccess: remove noinline variants of __strncpy_from_user() and friends Vineet Gupta
2020-01-14 20:08 ` [RFC 4/4] ARC: uaccess: use optimized generic __strnlen_user/__strncpy_from_user Vineet Gupta
2020-01-14 20:42 ` Arnd Bergmann
2020-01-14 21:36 ` Vineet Gupta
2020-01-14 21:49 ` Linus Torvalds
2020-01-14 22:14 ` Vineet Gupta
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