From: "Christoph Lameter (Ampere)" <cl@gentwo.org>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: Yang Shi <yang@os.amperecomputing.com>,
will@kernel.org, anshuman.khandual@arm.com, david@redhat.com,
scott@os.amperecomputing.com,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [v5 PATCH] arm64: mm: force write fault for atomic RMW instructions
Date: Fri, 28 Jun 2024 09:57:37 -0700 (PDT) [thread overview]
Message-ID: <773c8be7-eb73-010c-acea-1c2fefd65b84@gentwo.org> (raw)
In-Reply-To: <Zn7q3oL1AE8jdM-g@arm.com>
On Fri, 28 Jun 2024, Catalin Marinas wrote:
> On Wed, Jun 26, 2024 at 12:18:30PM -0700, Yang Shi wrote:
>> @@ -568,6 +596,12 @@ static int __kprobes do_page_fault(unsigned long far, unsigned long esr,
>> if (!vma)
>> goto lock_mmap;
>>
>> + if ((vm_flags & VM_READ) && (vma->vm_flags & VM_WRITE) &&
>> + is_el0_atomic_instr(regs)) {
>> + vm_flags = VM_WRITE;
>> + mm_flags |= FAULT_FLAG_WRITE;
>> + }
>
> The patch looks fine now and AFAICT there's no ABI change.
>
> However, before deciding whether to merge this patch, I'd like to
> understand why OpenJDK cannot use madvise(MADV_POPULATE_WRITE). This
> would be the portable (Linux) solution that works better on
> architectures without such atomic instructions (e.g. arm64 without LSE
> atomics). So fixing user-space would be my preferred solution.
Doing so would be requesting application code changes that are linux
and ARM64 specific from applications running on Linux. A lot of these are
proprietary.
next prev parent reply other threads:[~2024-06-28 16:57 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-06-26 19:18 Yang Shi
2024-06-28 16:54 ` Catalin Marinas
2024-06-28 16:57 ` Christoph Lameter (Ampere) [this message]
2024-06-28 17:24 ` Catalin Marinas
2024-06-28 18:20 ` Yang Shi
2024-07-01 19:43 ` Catalin Marinas
2024-07-02 10:26 ` Ryan Roberts
2024-07-02 11:22 ` David Hildenbrand
2024-07-02 12:36 ` Ryan Roberts
2024-07-02 12:58 ` David Hildenbrand
2024-07-02 13:26 ` Ryan Roberts
2024-07-02 13:50 ` David Hildenbrand
2024-07-02 14:51 ` Ryan Roberts
2024-07-15 13:09 ` Ryan Roberts
2024-07-02 22:21 ` Yang Shi
2024-07-04 10:03 ` Catalin Marinas
2024-07-05 17:05 ` Christoph Lameter (Ampere)
2024-07-05 18:24 ` Catalin Marinas
2024-07-05 18:51 ` Christoph Lameter (Ampere)
2024-07-06 9:47 ` Catalin Marinas
2024-07-09 17:56 ` Yang Shi
2024-07-09 18:35 ` Catalin Marinas
2024-07-09 22:29 ` Yang Shi
2024-07-10 9:22 ` Catalin Marinas
2024-07-10 18:43 ` Yang Shi
2024-07-11 17:43 ` Catalin Marinas
2024-07-11 18:17 ` Yang Shi
2024-08-13 17:09 ` Yang Shi
2024-08-21 10:18 ` Catalin Marinas
2024-08-21 11:32 ` Dev Jain
2024-08-23 9:59 ` Will Deacon
2024-06-28 18:26 ` Christoph Lameter (Ampere)
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