From: Nadav Amit <namit@vmware.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Nicholas Piggin <npiggin@gmail.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
"linux-csky@vger.kernel.org" <linux-csky@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
linux-s390 <linux-s390@vger.kernel.org>,
Andy Lutomirski <luto@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Will Deacon <will@kernel.org>, X86 ML <x86@kernel.org>,
Yu Zhao <yuzhao@google.com>
Subject: Re: [RFC 11/20] mm/tlb: remove arch-specific tlb_start/end_vma()
Date: Tue, 2 Feb 2021 09:54:36 +0000 [thread overview]
Message-ID: <9100B8AE-129A-4E13-8F01-7B9C14C98B4C@vmware.com> (raw)
In-Reply-To: <YBkb8yKSUKTPJvxk@hirez.programming.kicks-ass.net>
> On Feb 2, 2021, at 1:31 AM, Peter Zijlstra <peterz@infradead.org> wrote:
>
> On Tue, Feb 02, 2021 at 07:20:55AM +0000, Nadav Amit wrote:
>> Arm does not define tlb_end_vma, and consequently it flushes the TLB after
>> each VMA. I suspect it is not intentional.
>
> ARM is one of those that look at the VM_EXEC bit to explicitly flush
> ITLB IIRC, so it has to.
Hmm… I don’t think Arm is doing that. At least arm64 does not use the
default tlb_flush(), and it does not seem to consider VM_EXEC (at least in
this path):
static inline void tlb_flush(struct mmu_gather *tlb)
{
struct vm_area_struct vma = TLB_FLUSH_VMA(tlb->mm, 0);
bool last_level = !tlb->freed_tables;
unsigned long stride = tlb_get_unmap_size(tlb);
int tlb_level = tlb_get_level(tlb);
/*
* If we're tearing down the address space then we only care about
* invalidating the walk-cache, since the ASID allocator won't
* reallocate our ASID without invalidating the entire TLB.
*/
if (tlb->mm_exiting) {
if (!last_level)
flush_tlb_mm(tlb->mm);
return;
}
__flush_tlb_range(&vma, tlb->start, tlb->end, stride,
last_level, tlb_level);
}
next prev parent reply other threads:[~2021-02-02 9:56 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-31 0:11 [RFC 00/20] TLB batching consolidation and enhancements Nadav Amit
2021-01-31 0:11 ` [RFC 11/20] mm/tlb: remove arch-specific tlb_start/end_vma() Nadav Amit
2021-02-01 12:09 ` Peter Zijlstra
2021-02-02 6:41 ` Nicholas Piggin
2021-02-02 7:20 ` Nadav Amit
2021-02-02 9:31 ` Peter Zijlstra
2021-02-02 9:54 ` Nadav Amit [this message]
2021-02-02 11:04 ` Peter Zijlstra
2021-01-31 0:39 ` [RFC 00/20] TLB batching consolidation and enhancements Andy Lutomirski
2021-01-31 1:08 ` Nadav Amit
2021-01-31 3:30 ` Nicholas Piggin
2021-01-31 7:57 ` Nadav Amit
2021-01-31 8:14 ` Nadav Amit
2021-02-01 12:44 ` Peter Zijlstra
2021-02-02 7:14 ` Nicholas Piggin
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