Re: [Qemu-devel] [RFC 35/38] cputlb: use cpu_tcg_sched_work for tlb_flush_all

[Alex Bennée]

Emilio G. Cota <address@hidden> writes:

> Signed-off-by: Emilio G. Cota <address@hidden>
> ---
>  cputlb.c | 41 +++++++++++------------------------------
>  1 file changed, 11 insertions(+), 30 deletions(-)

I bisected my Jessie boot failure to this commit. Before it boots up
fine, here it just hangs before the kernel starts init.

17:05 address@hidden/x86_64  [qemu.git/bisect:???]
>./arm-softmmu/qemu-system-arm -machine virt -cpu cortex-a15 -machine
type=virt -display none -serial telnet:127.0.0.1:4444 -monitor stdio
-smp 4 -m 4096 -kernel ../images/aarch32-current-linux-kernel-only.img
 --append "console=ttyAMA0 root=/dev/vda1" -drive
 file=../images/jessie-arm32.qcow2,id=myblock,index=0,if=none -device
 virtio-b
 lk-device,drive=myblock -netdev user,id=unet,hostfwd=tcp::2222-:22
 -device virtio-net-device,netdev=unet -D /tmp/qemu.log -d un
 imp -name debug-threads=on

See people.linaro.org/~alex.bennee/images


>
> diff --git a/cputlb.c b/cputlb.c
> index 1b3673e..d81a4eb 100644
> --- a/cputlb.c
> +++ b/cputlb.c
> @@ -73,43 +73,24 @@ void tlb_flush(CPUState *cpu, int flush_global)
>      tlb_flush_count++;
>  }
>  
> -struct TLBFlushParams {
> -    CPUState *cpu;
> -    int flush_global;
> -};
> -
> -static void tlb_flush_async_work(void *opaque)
> +static void __tlb_flush_all(void *arg)
>  {
> -    struct TLBFlushParams *params = opaque;
> +    CPUState *cpu;
> +    int flush_global = *(int *)arg;
>  
> -    tlb_flush(params->cpu, params->flush_global);
> -    g_free(params);
> +    CPU_FOREACH(cpu) {
> +        tlb_flush(cpu, flush_global);
> +    }
> +    g_free(arg);
>  }
>  
>  void tlb_flush_all(int flush_global)
>  {
> -    CPUState *cpu;
> -    struct TLBFlushParams *params;
> +    int *arg = g_malloc(sizeof(*arg));
>  
> -#if 0 /* MTTCG */
> -    CPU_FOREACH(cpu) {
> -        tlb_flush(cpu, flush_global);
> -    }
> -#else
> -    CPU_FOREACH(cpu) {
> -        if (qemu_cpu_is_self(cpu)) {
> -            /* async_run_on_cpu handle this case but this just avoid a malloc
> -             * here.
> -             */
> -            tlb_flush(cpu, flush_global);
> -        } else {
> -            params = g_malloc(sizeof(struct TLBFlushParams));
> -            params->cpu = cpu;
> -            params->flush_global = flush_global;
> -            async_run_on_cpu(cpu, tlb_flush_async_work, params);
> -        }
> -    }
> -#endif /* MTTCG */
> +    *arg = flush_global;
> +    tb_lock();
> +    cpu_tcg_sched_work(current_cpu, __tlb_flush_all, arg);
>  }
>  
>  static inline void tlb_flush_entry(CPUTLBEntry *tlb_entry, target_ulong addr)

-- 
Alex Bennée