[PATCH] drm/amdgpu/mes: fix mes ring buffer overflow

Xiao, Jack Jack.Xiao at amd.com
Tue Jul 23 03:08:18 UTC 2024


[AMD Official Use Only - AMD Internal Distribution Only]

> Does this patch fix it?
https://patchwork.freedesktop.org/patch/605437/

No, please do not check in the patch, it will make my fix not working.

Regards,
Jack
________________________________
From: Alex Deucher <alexdeucher at gmail.com>
Sent: Tuesday, 23 July 2024 03:52
To: Christian König <ckoenig.leichtzumerken at gmail.com>
Cc: Xiao, Jack <Jack.Xiao at amd.com>; amd-gfx at lists.freedesktop.org <amd-gfx at lists.freedesktop.org>; Deucher, Alexander <Alexander.Deucher at amd.com>
Subject: Re: [PATCH] drm/amdgpu/mes: fix mes ring buffer overflow

Does this patch fix it?
https://patchwork.freedesktop.org/patch/605437/

Alex

On Mon, Jul 22, 2024 at 7:21 AM Christian König
<ckoenig.leichtzumerken at gmail.com> wrote:
>
> What I meant is that the MES ring is now to small for the number of packets written to it.
>
> Either reduce the num_hw_submission or increase the MES ring size.
>
> E.g. see this code here in amdgpu_ring_init:
>
>         if (ring->funcs->type == AMDGPU_RING_TYPE_KIQ)
>                 sched_hw_submission = max(sched_hw_submission, 256);
>         else if (ring == &adev->sdma.instance[0].page)
>                 sched_hw_submission = 256;
>
> We are basically just missing a case for the MES here as far as I can see.
>
> Regards,
> Christian.
>
> Am 22.07.24 um 10:46 schrieb Xiao, Jack:
>
> [AMD Official Use Only - AMD Internal Distribution Only]
>
>
> >> Can you try to reduce num_hw_submission for the MES ring?
>
> Smaller num_hw_submission should not help for this issue, for Mes work without drm scheduler like legacy kiq. Smaller num_hw_submission will result in smaller mes ring size and more waiting time.
>
> Regards,
> Jack
> ________________________________
> From: Christian König <ckoenig.leichtzumerken at gmail.com>
> Sent: Monday, 22 July 2024 16:20
> To: Xiao, Jack <Jack.Xiao at amd.com>; amd-gfx at lists.freedesktop.org <amd-gfx at lists.freedesktop.org>; Deucher, Alexander <Alexander.Deucher at amd.com>
> Subject: Re: [PATCH] drm/amdgpu/mes: fix mes ring buffer overflow
>
> Thx, but in that case this patch here then won't help either it just mitigates the problem.
>
> Can you try to reduce num_hw_submission for the MES ring?
>
> Thanks,
> Christian.
>
> Am 22.07.24 um 05:27 schrieb Xiao, Jack:
>
> [AMD Official Use Only - AMD Internal Distribution Only]
>
>
> >> I think we rather need to increase the MES ring size instead.
>
> Unfortunately, it doesn't work. I guess mes firmware has limitation.
>
> Regards,
> Jack
>
> ________________________________
> From: Christian König <ckoenig.leichtzumerken at gmail.com>
> Sent: Friday, 19 July 2024 23:44
> To: Xiao, Jack <Jack.Xiao at amd.com>; amd-gfx at lists.freedesktop.org <amd-gfx at lists.freedesktop.org>; Deucher, Alexander <Alexander.Deucher at amd.com>
> Subject: Re: [PATCH] drm/amdgpu/mes: fix mes ring buffer overflow
>
> Am 19.07.24 um 11:16 schrieb Jack Xiao:
> > wait memory room until enough before writing mes packets
> > to avoid ring buffer overflow.
> >
> > Signed-off-by: Jack Xiao <Jack.Xiao at amd.com>
> > ---
> >   drivers/gpu/drm/amd/amdgpu/mes_v11_0.c | 18 ++++++++++++++----
> >   drivers/gpu/drm/amd/amdgpu/mes_v12_0.c | 18 ++++++++++++++----
> >   2 files changed, 28 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/mes_v11_0.c b/drivers/gpu/drm/amd/amdgpu/mes_v11_0.c
> > index 8ce51b9236c1..68c74adf79f1 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/mes_v11_0.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/mes_v11_0.c
> > @@ -168,7 +168,7 @@ static int mes_v11_0_submit_pkt_and_poll_completion(struct amdgpu_mes *mes,
> >        const char *op_str, *misc_op_str;
> >        unsigned long flags;
> >        u64 status_gpu_addr;
> > -     u32 status_offset;
> > +     u32 seq, status_offset;
> >        u64 *status_ptr;
> >        signed long r;
> >        int ret;
> > @@ -196,6 +196,13 @@ static int mes_v11_0_submit_pkt_and_poll_completion(struct amdgpu_mes *mes,
> >        if (r)
> >                goto error_unlock_free;
> >
> > +     seq = ++ring->fence_drv.sync_seq;
> > +     r = amdgpu_fence_wait_polling(ring,
> > +                                   seq - ring->fence_drv.num_fences_mask,
> > +                                   timeout);
> > +     if (r < 1)
> > +             goto error_undo;
> > +
> >        api_status = (struct MES_API_STATUS *)((char *)pkt + api_status_off);
> >        api_status->api_completion_fence_addr = status_gpu_addr;
> >        api_status->api_completion_fence_value = 1;
> > @@ -208,8 +215,7 @@ static int mes_v11_0_submit_pkt_and_poll_completion(struct amdgpu_mes *mes,
> >        mes_status_pkt.header.dwsize = API_FRAME_SIZE_IN_DWORDS;
> >        mes_status_pkt.api_status.api_completion_fence_addr =
> >                ring->fence_drv.gpu_addr;
> > -     mes_status_pkt.api_status.api_completion_fence_value =
> > -             ++ring->fence_drv.sync_seq;
> > +     mes_status_pkt.api_status.api_completion_fence_value = seq;
> >
> >        amdgpu_ring_write_multiple(ring, &mes_status_pkt,
> >                                   sizeof(mes_status_pkt) / 4);
> > @@ -229,7 +235,7 @@ static int mes_v11_0_submit_pkt_and_poll_completion(struct amdgpu_mes *mes,
> >                dev_dbg(adev->dev, "MES msg=%d was emitted\n",
> >                        x_pkt->header.opcode);
> >
> > -     r = amdgpu_fence_wait_polling(ring, ring->fence_drv.sync_seq, timeout);
> > +     r = amdgpu_fence_wait_polling(ring, seq, timeout);
> >        if (r < 1 || !*status_ptr) {
> >
> >                if (misc_op_str)
> > @@ -252,6 +258,10 @@ static int mes_v11_0_submit_pkt_and_poll_completion(struct amdgpu_mes *mes,
> >        amdgpu_device_wb_free(adev, status_offset);
> >        return 0;
> >
> > +error_undo:
> > +     dev_err(adev->dev, "MES ring buffer is full.\n");
> > +     amdgpu_ring_undo(ring);
> > +
> >   error_unlock_free:
> >        spin_unlock_irqrestore(&mes->ring_lock, flags);
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/mes_v12_0.c b/drivers/gpu/drm/amd/amdgpu/mes_v12_0.c
> > index c9f74231ad59..48e01206bcc4 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/mes_v12_0.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/mes_v12_0.c
> > @@ -154,7 +154,7 @@ static int mes_v12_0_submit_pkt_and_poll_completion(struct amdgpu_mes *mes,
> >        const char *op_str, *misc_op_str;
> >        unsigned long flags;
> >        u64 status_gpu_addr;
> > -     u32 status_offset;
> > +     u32 seq, status_offset;
> >        u64 *status_ptr;
> >        signed long r;
> >        int ret;
> > @@ -182,6 +182,13 @@ static int mes_v12_0_submit_pkt_and_poll_completion(struct amdgpu_mes *mes,
> >        if (r)
> >                goto error_unlock_free;
> >
> > +     seq = ++ring->fence_drv.sync_seq;
> > +     r = amdgpu_fence_wait_polling(ring,
> > +                                   seq - ring->fence_drv.num_fences_mask,
>
> That's what's amdgpu_fence_emit_polling() does anyway.
>
> So this here just moves the polling a bit earlier.
>
> I think we rather need to increase the MES ring size instead.
>
> Regards,
> Christian.
>
>
> > +                                   timeout);
> > +     if (r < 1)
> > +             goto error_undo;
> > +
> >        api_status = (struct MES_API_STATUS *)((char *)pkt + api_status_off);
> >        api_status->api_completion_fence_addr = status_gpu_addr;
> >        api_status->api_completion_fence_value = 1;
> > @@ -194,8 +201,7 @@ static int mes_v12_0_submit_pkt_and_poll_completion(struct amdgpu_mes *mes,
> >        mes_status_pkt.header.dwsize = API_FRAME_SIZE_IN_DWORDS;
> >        mes_status_pkt.api_status.api_completion_fence_addr =
> >                ring->fence_drv.gpu_addr;
> > -     mes_status_pkt.api_status.api_completion_fence_value =
> > -             ++ring->fence_drv.sync_seq;
> > +     mes_status_pkt.api_status.api_completion_fence_value = seq;
> >
> >        amdgpu_ring_write_multiple(ring, &mes_status_pkt,
> >                                   sizeof(mes_status_pkt) / 4);
> > @@ -215,7 +221,7 @@ static int mes_v12_0_submit_pkt_and_poll_completion(struct amdgpu_mes *mes,
> >                dev_dbg(adev->dev, "MES msg=%d was emitted\n",
> >                        x_pkt->header.opcode);
> >
> > -     r = amdgpu_fence_wait_polling(ring, ring->fence_drv.sync_seq, timeout);
> > +     r = amdgpu_fence_wait_polling(ring, seq, timeout);
> >        if (r < 1 || !*status_ptr) {
> >
> >                if (misc_op_str)
> > @@ -238,6 +244,10 @@ static int mes_v12_0_submit_pkt_and_poll_completion(struct amdgpu_mes *mes,
> >        amdgpu_device_wb_free(adev, status_offset);
> >        return 0;
> >
> > +error_undo:
> > +     dev_err(adev->dev, "MES ring buffer is full.\n");
> > +     amdgpu_ring_undo(ring);
> > +
> >   error_unlock_free:
> >        spin_unlock_irqrestore(&mes->ring_lock, flags);
> >
>
>
>
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