[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [patch 35/37] x86/smpboot: Support parallel startup of secondary CPUs
- To: Brian Gerst <brgerst@xxxxxxxxx>
- From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
- Date: Mon, 24 Apr 2023 19:58:36 +0200
- Cc: LKML <linux-kernel@xxxxxxxxxxxxxxx>, x86@xxxxxxxxxx, David Woodhouse <dwmw@xxxxxxxxxxxxx>, Andrew Cooper <andrew.cooper3@xxxxxxxxxx>, Arjan van de Veen <arjan@xxxxxxxxxxxxxxx>, Paolo Bonzini <pbonzini@xxxxxxxxxx>, Paul McKenney <paulmck@xxxxxxxxxx>, Tom Lendacky <thomas.lendacky@xxxxxxx>, Sean Christopherson <seanjc@xxxxxxxxxx>, Oleksandr Natalenko <oleksandr@xxxxxxxxxxxxxx>, Paul Menzel <pmenzel@xxxxxxxxxxxxx>, "Guilherme G. Piccoli" <gpiccoli@xxxxxxxxxx>, Piotr Gorski <lucjan.lucjanov@xxxxxxxxx>, David Woodhouse <dwmw@xxxxxxxxxxxx>, Usama Arif <usama.arif@xxxxxxxxxxxxx>, Juergen Gross <jgross@xxxxxxxx>, Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>, xen-devel@xxxxxxxxxxxxxxxxxxxx, Russell King <linux@xxxxxxxxxxxxxxx>, Arnd Bergmann <arnd@xxxxxxxx>, linux-arm-kernel@xxxxxxxxxxxxxxxxxxx, Catalin Marinas <catalin.marinas@xxxxxxx>, Will Deacon <will@xxxxxxxxxx>, Guo Ren <guoren@xxxxxxxxxx>, linux-csky@xxxxxxxxxxxxxxx, Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>, linux-mips@xxxxxxxxxxxxxxx, "James E.J. Bottomley" <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>, Helge Deller <deller@xxxxxx>, linux-parisc@xxxxxxxxxxxxxxx, Paul Walmsley <paul.walmsley@xxxxxxxxxx>, Palmer Dabbelt <palmer@xxxxxxxxxxx>, linux-riscv@xxxxxxxxxxxxxxxxxxx, Mark Rutland <mark.rutland@xxxxxxx>, Sabin Rapan <sabrapan@xxxxxxxxxx>
- Delivery-date: Mon, 24 Apr 2023 17:59:02 +0000
- List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
On Sat, Apr 15 2023 at 23:06, Thomas Gleixner wrote:
> On Sat, Apr 15 2023 at 09:22, Brian Gerst wrote:
>> On Fri, Apr 14, 2023 at 7:45 PM Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
>>> @@ -248,10 +311,20 @@ SYM_INNER_LABEL(secondary_startup_64_no_
>>> *
>>> * RDX contains the per-cpu offset
>>> */
>>> - movq pcpu_hot + X86_current_task(%rdx), %rax
>>> - movq TASK_threadsp(%rax), %rsp
>>> + movq pcpu_hot + X86_top_of_stack(%rdx), %rsp
>>
>> Switching to using pcpu_hot.top_of_stack is ok, but it's not
>> completely equivalent. top_of_stack points to the end of the pt_regs
>> structure, while the kernel stack starts below pt_regs even for kernel
>> threads. So you need to subtract PTREGS_SIZE from the stack pointer
>> after this.
>>
>> This change should also be a separate patch.
>
> You're right on both counts.
Actually no. We can't do that as this breaks suspend/resume (again).
/me drops it.
|
