From: Peter Zijlstra <peterz@infradead.org>
To: Andy Lutomirski <luto@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>,
LKML <linux-kernel@vger.kernel.org>, X86 ML <x86@kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Arnd Bergmann <arnd@arndb.de>,
linux-arch <linux-arch@vger.kernel.org>,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
Linux-MM <linux-mm@kvack.org>, Anton Blanchard <anton@ozlabs.org>
Subject: Re: [PATCH 6/8] lazy tlb: shoot lazies, a non-refcounting lazy tlb option
Date: Mon, 30 Nov 2020 10:34:17 +0100 [thread overview]
Message-ID: <20201130093417.GI3092@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20201130093000.GM2414@hirez.programming.kicks-ass.net>
On Mon, Nov 30, 2020 at 10:30:00AM +0100, Peter Zijlstra wrote:
> On Sat, Nov 28, 2020 at 07:54:57PM -0800, Andy Lutomirski wrote:
> > This means that mm_cpumask operations won't need to be full barriers
> > forever, and we might not want to take the implied full barriers in
> > set_bit() and clear_bit() for granted.
>
> There is no implied full barrier for those ops.
Neither ARM nor Power implies any ordering on those ops. But Power has
some of the worst atomic performance in the world despite of that.
IIRC they don't do their LL/SC in L1.
next prev parent reply other threads:[~2020-11-30 9:34 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-28 16:01 [PATCH 0/8] shoot lazy tlbs Nicholas Piggin
2020-11-28 16:01 ` [PATCH 1/8] lazy tlb: introduce exit_lazy_tlb Nicholas Piggin
2020-11-29 0:38 ` Andy Lutomirski
2020-12-02 2:49 ` Nicholas Piggin
2020-11-28 16:01 ` [PATCH 2/8] x86: use exit_lazy_tlb rather than membarrier_mm_sync_core_before_usermode Nicholas Piggin
2020-11-28 17:55 ` Andy Lutomirski
2020-12-02 2:49 ` Nicholas Piggin
2020-12-03 5:09 ` Andy Lutomirski
2020-12-05 8:00 ` Nicholas Piggin
2020-12-05 16:11 ` Andy Lutomirski
2020-12-05 23:14 ` Nicholas Piggin
2020-12-06 0:36 ` Andy Lutomirski
2020-12-06 3:59 ` Nicholas Piggin
2020-12-11 0:11 ` Andy Lutomirski
2020-12-14 4:07 ` Nicholas Piggin
2020-12-14 5:53 ` Nicholas Piggin
2020-11-30 14:57 ` Mathieu Desnoyers
2020-11-28 16:01 ` [PATCH 3/8] x86: remove ARCH_HAS_SYNC_CORE_BEFORE_USERMODE Nicholas Piggin
2020-11-28 16:01 ` [PATCH 4/8] lazy tlb: introduce lazy mm refcount helper functions Nicholas Piggin
2020-11-28 16:01 ` [PATCH 5/8] lazy tlb: allow lazy tlb mm switching to be configurable Nicholas Piggin
2020-11-29 0:36 ` Andy Lutomirski
2020-12-02 2:49 ` Nicholas Piggin
2020-11-28 16:01 ` [PATCH 6/8] lazy tlb: shoot lazies, a non-refcounting lazy tlb option Nicholas Piggin
2020-11-29 3:54 ` Andy Lutomirski
2020-11-29 20:16 ` Andy Lutomirski
2020-11-30 9:25 ` Peter Zijlstra
2020-11-30 18:31 ` Andy Lutomirski
2020-12-01 21:27 ` Will Deacon
2020-12-01 21:50 ` Andy Lutomirski
2020-12-01 23:04 ` Will Deacon
2020-12-02 3:47 ` Nicholas Piggin
2020-12-03 5:05 ` Andy Lutomirski
2020-12-03 17:03 ` Alexander Gordeev
2020-12-03 17:14 ` Andy Lutomirski
2020-12-03 18:33 ` Alexander Gordeev
2020-11-30 9:26 ` Peter Zijlstra
2020-11-30 9:30 ` Peter Zijlstra
2020-11-30 9:34 ` Peter Zijlstra [this message]
2020-12-02 3:09 ` Nicholas Piggin
2020-12-02 11:17 ` Peter Zijlstra
2020-12-02 12:45 ` Peter Zijlstra
2020-12-02 14:19 ` Peter Zijlstra
2020-12-02 14:38 ` Andy Lutomirski
2020-12-02 16:29 ` Peter Zijlstra
2020-11-28 16:01 ` [PATCH 7/8] powerpc: use lazy mm refcount helper functions Nicholas Piggin
2020-11-28 16:01 ` [PATCH 8/8] powerpc/64s: enable MMU_LAZY_TLB_SHOOTDOWN Nicholas Piggin
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