[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [RFC DEBUG PATCH 3/3] translate-a64: fix lookup_tb_ptr
From: |
Emilio G. Cota |
Subject: |
Re: [Qemu-devel] [RFC DEBUG PATCH 3/3] translate-a64: fix lookup_tb_ptr hang (DEBUG!) |
Date: |
Sun, 11 Jun 2017 01:07:30 -0400 |
User-agent: |
Mutt/1.5.24 (2015-08-30) |
On Sat, Jun 10, 2017 at 09:59:19 -0700, Richard Henderson wrote:
> On 06/10/2017 01:51 AM, Alex Bennée wrote:
> >I would agree with Emilio that we revert but I can't quite shake the
> >feeling we are missing an underlying problem. Would just skipping the
> >htable lookup (but keeping the tb_jmp_cache) be an OK fix for now?
>
> I agree. It seems like there's some real problem that this is uncovering.
>
> Dropping the htable lookup is certainly ok by me. If that's enough to
> un-stick your regression testing for aarch64 guest.
Unfortunately not checking the htable isn't enough to fix it for me.
I spent a few hours on Friday trying (and failing) to understand
what's going on. Regarding interrupts, I see *more* TB_EXIT_INTERRUPT
exits than without the patch, so my current best guess is that this is
a livelock kind of thing.
I'll keep digging, but regardless I think we should revert
e75449a346 ("target/aarch64: optimize indirect branches") ASAP, and
then reenable the feature ("revert the revert") once we get to the
bottom of this.
E.
- [Qemu-devel] [RFC DEBUG PATCH 0/3] debug patch for lookup-ptr hang, Alex Bennée, 2017/06/09
- [Qemu-devel] [RFC DEBUG PATCH 1/3] vl: Fix broken thread=xxx option of the --accel parameter, Alex Bennée, 2017/06/09
- [Qemu-devel] [RFC DEBUG PATCH 2/3] tcg-runtime: light re-factor of lookup_tb_ptr, Alex Bennée, 2017/06/09
- [Qemu-devel] [RFC DEBUG PATCH 3/3] translate-a64: fix lookup_tb_ptr hang (DEBUG!), Alex Bennée, 2017/06/09
- Re: [Qemu-devel] [RFC DEBUG PATCH 3/3] translate-a64: fix lookup_tb_ptr hang (DEBUG!), Richard Henderson, 2017/06/09
- Re: [Qemu-devel] [RFC DEBUG PATCH 3/3] translate-a64: fix lookup_tb_ptr hang (DEBUG!), Alex Bennée, 2017/06/10
- Re: [Qemu-devel] [RFC DEBUG PATCH 3/3] translate-a64: fix lookup_tb_ptr hang (DEBUG!), Richard Henderson, 2017/06/10
- Re: [Qemu-devel] [RFC DEBUG PATCH 3/3] translate-a64: fix lookup_tb_ptr hang (DEBUG!),
Emilio G. Cota <=
- Re: [Qemu-devel] [RFC DEBUG PATCH 3/3] translate-a64: fix lookup_tb_ptr hang (DEBUG!), Alex Bennée, 2017/06/12
- [Qemu-devel] [PATCH] target/aarch64: exit to main loop after handling MSR, Emilio G. Cota, 2017/06/13
- Re: [Qemu-devel] [PATCH] target/aarch64: exit to main loop after handling MSR, no-reply, 2017/06/13
- Re: [Qemu-devel] [PATCH] target/aarch64: exit to main loop after handling MSR, Richard Henderson, 2017/06/14
- Re: [Qemu-devel] [PATCH] target/aarch64: exit to main loop after handling MSR, Paolo Bonzini, 2017/06/14
- Re: [Qemu-devel] [PATCH] target/aarch64: exit to main loop after handling MSR, Alex Bennée, 2017/06/14
- Re: [Qemu-devel] [PATCH] target/aarch64: exit to main loop after handling MSR, Paolo Bonzini, 2017/06/14
- Re: [Qemu-devel] [PATCH] target/aarch64: exit to main loop after handling MSR, Alex Bennée, 2017/06/14
- Re: [Qemu-devel] [PATCH] target/aarch64: exit to main loop after handling MSR, Paolo Bonzini, 2017/06/14
- Re: [Qemu-devel] [PATCH] target/aarch64: exit to main loop after handling MSR, Alex Bennée, 2017/06/14