[PATCH v4] drm/amdgpu: add new trace event for page table update v3
Nirmoy
nirmodas at amd.com
Wed Aug 19 12:45:21 UTC 2020
Hi Christian,
On 8/19/20 2:08 PM, Christian König wrote:
> Am 19.08.20 um 13:52 schrieb Shashank Sharma:
>> On 13/08/20 1:28 pm, Christian König wrote:
>>> Am 13.08.20 um 05:04 schrieb Shashank Sharma:
>>>> This patch adds a new trace event to track the PTE update
>>>> events. This specific event will provide information like:
>>>> - start and end of virtual memory mapping
>>>> - HW engine flags for the map
>>>> - physical address for mapping
>>>>
>>>> This will be particularly useful for memory profiling tools
>>>> (like RMV) which are monitoring the page table update events.
>>>>
>>>> V2: Added physical address lookup logic in trace point
>>>> V3: switch to use __dynamic_array
>>>> added nptes int the TPprint arguments list
>>>> added page size in the arg list
>>>> V4: Addressed Christian's review comments
>>>> add start/end instead of seg
>>>> use incr instead of page_sz to be accurate
>>>>
>>>> Cc: Christian König <christian.koenig at amd.com>
>>>> Cc: Alex Deucher <alexander.deucher at amd.com>
>>>> Signed-off-by: Christian König <christian.koenig at amd.com>
>>>> Signed-off-by: Shashank Sharma <shashank.sharma at amd.com>
>>>> ---
>>>> drivers/gpu/drm/amd/amdgpu/amdgpu_trace.h | 37
>>>> +++++++++++++++++++++++
>>>> drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 9 ++++--
>>>> 2 files changed, 44 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_trace.h
>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_trace.h
>>>> index 63e734a125fb..df12cf8466c2 100644
>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_trace.h
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_trace.h
>>>> @@ -321,6 +321,43 @@ DEFINE_EVENT(amdgpu_vm_mapping, amdgpu_vm_bo_cs,
>>>> TP_ARGS(mapping)
>>>> );
>>>> +TRACE_EVENT(amdgpu_vm_update_ptes,
>>>> + TP_PROTO(struct amdgpu_vm_update_params *p,
>>>> + uint64_t start, uint64_t end,
>>>> + unsigned int nptes, uint64_t dst,
>>>> + uint64_t incr, uint64_t flags),
>>>> + TP_ARGS(p, start, end, nptes, dst, incr, flags),
>>>> + TP_STRUCT__entry(
>>>> + __field(u64, start)
>>>> + __field(u64, end)
>>>> + __field(u64, flags)
>>>> + __field(unsigned int, nptes)
>>>> + __field(u64, incr)
>>>> + __dynamic_array(u64, dst, nptes)
>>> As discussed with the trace subsystem maintainer we need to add the pid
>>> and probably the VM context ID we use here to identify the updated VM.
>>>
>>> Christian.
>> I printed both vm->task_info.pid Vs current->pid for testing, and I
>> can see different values coming out of .
>>
>> gnome-shell-2114 [011] 41.812894: amdgpu_vm_update_ptes:
>> start:0x0800102e80 end:0x0800102e82, flags:0x80, incr:4096, pid=2128
>> vmid=0 cpid=2114
>>
>> pid is vm->task_info.pid=2128 whereas cpid=2114 is current.pid.
>>
>> Which is the one we want to send with the event ?
>
> That is vm->task_info.pid, since this is the PID which is using the VM
> for command submission.
Noob question:
Why these two pids are different ? Is it like that, the cpid-2114
process created a page/memory-area and now pid-2128 using that
page/memory-area to submit a command ?
Regards,
Nirmoy
>
>> Trace event by default seems to be adding the process name and id at
>> the header of the event (gnome-shell-2114), which is same as current.pid
>>
>>
>> Also, is it ok to extract vmid from job->vmid ?
>
> Only in trace_amdgpu_vm_grab_id(), in all other cases it's probably
> not assigned yet.
>
> Christian.
>
>>
>>
>> Regards
>>
>> Shashank
>>
>>>> + ),
>>>> +
>>>> + TP_fast_assign(
>>>> + unsigned int i;
>>>> +
>>>> + __entry->start = start;
>>>> + __entry->end = end;
>>>> + __entry->flags = flags;
>>>> + __entry->incr = incr;
>>>> + __entry->nptes = nptes;
>>>> + for (i = 0; i < nptes; ++i) {
>>>> + u64 addr = p->pages_addr ? amdgpu_vm_map_gart(
>>>> + p->pages_addr, dst) : dst;
>>>> +
>>>> + ((u64 *)__get_dynamic_array(dst))[i] = addr;
>>>> + dst += incr;
>>>> + }
>>>> + ),
>>>> + TP_printk("start:0x%010llx end:0x%010llx, flags:0x%llx,
>>>> incr:%llu,"
>>>> + " dst:\n%s", __entry->start, __entry->end, __entry->flags,
>>>> + __entry->incr, __print_array(
>>>> + __get_dynamic_array(dst), __entry->nptes, 8))
>>>> +);
>>>> +
>>>> TRACE_EVENT(amdgpu_vm_set_ptes,
>>>> TP_PROTO(uint64_t pe, uint64_t addr, unsigned count,
>>>> uint32_t incr, uint64_t flags, bool direct),
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>>>> index 71e005cf2952..b5dbb5e8bc61 100644
>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>>>> @@ -1513,17 +1513,22 @@ static int amdgpu_vm_update_ptes(struct
>>>> amdgpu_vm_update_params *params,
>>>> do {
>>>> uint64_t upd_end = min(entry_end, frag_end);
>>>> unsigned nptes = (upd_end - frag_start) >> shift;
>>>> + uint64_t upd_flags = flags | AMDGPU_PTE_FRAG(frag);
>>>> /* This can happen when we set higher level PDs to
>>>> * silent to stop fault floods.
>>>> */
>>>> nptes = max(nptes, 1u);
>>>> +
>>>> + trace_amdgpu_vm_update_ptes(params, frag_start, upd_end,
>>>> + nptes, dst, incr,
>>>> + upd_flags);
>>>> amdgpu_vm_update_flags(params, pt, cursor.level,
>>>> pe_start, dst, nptes, incr,
>>>> - flags | AMDGPU_PTE_FRAG(frag));
>>>> + upd_flags);
>>>> pe_start += nptes * 8;
>>>> - dst += (uint64_t)nptes * AMDGPU_GPU_PAGE_SIZE << shift;
>>>> + dst += nptes * incr;
>>>> frag_start = upd_end;
>>>> if (frag_start >= frag_end) {
>
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