Re: [PATCH] drm/xe: Remove unused xe_vma_flush tracepoint

[Steven Rostedt <rostedt@goodmis.org>]

On Tue, 3 Nov 2026 16:35:44 +0530
Sowmya Torra <sowmyatorra@gmail.com> wrote:

> Hello everyone,
> 
> I have a small question about measuring memory savings for tracepoint
> cleanup patches.
> 
> For my `xe_vma_flush` patch, I compared `xe_trace_bo.o` before and
> after the change using the `size` command and found a reduction of 452
> bytes.
> 
> I measured the compiled object file, not the actual memory usage when
> the module is loaded. Is this measurement enough, or should I also
> check the size of the final `.ko` module or measure the runtime memory
> usage?
> 
> I just wanted to make sure I'm measuring it the right way.

You are correct.

The 5K measurement is for TRACE_EVENT() which is really defined as:

#define TRACE_EVENT(foo..) DECLARE_EVENT_CLASS(foo, ...) DEFINE_EVENT(foo, ...)

where most of the heavy lifting is in that DECLARE_EVENT_CLASS(). I
created a way to split up events when they had the same info so that
each event didn't re-define the same code over and over.

Hence, TRACE_EVENT() is around 5K where each DEFINE_EVENT() is much
less, and can vary depending on configs.

-- Steve


> 
> BestRegards,
> Sowmya
> 
> On Tue, Nov 3, 2026 at 12:14 AM Torra Sowmya <sowmyatorra@gmail.com> wrote:
> >
> > Commit f3e9b1f43458 ("drm/xe: Remove async worker and rework sync
> > binds") removed the async worker and its calls to
> > trace_xe_vma_flush(), leaving the event definition unused.
> >
> > Remove the definition from xe_trace_bo.h to avoid generating code
> > and data for an event with no remaining callers.
> >
> > With the tested x86-64 configuration, size reports a reduction of
> > 452 bytes in xe_trace_bo.o, from 20262 to 19810 bytes: 156 bytes
> > in text and 296 bytes in data.
> >
> > Signed-off-by: Torra Sowmya <sowmyatorra@gmail.com>
> > ---
> >  drivers/gpu/drm/xe/xe_trace_bo.h | 5 -----
> >  1 file changed, 5 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/xe/xe_trace_bo.h b/drivers/gpu/drm/xe/xe_trace_bo.h
> > index 86323cf3be2c..72c4107adc13 100644
> > --- a/drivers/gpu/drm/xe/xe_trace_bo.h
> > +++ b/drivers/gpu/drm/xe/xe_trace_bo.h
> > @@ -115,11 +115,6 @@ DECLARE_EVENT_CLASS(xe_vma,
> >                               __entry->end, __entry->ptr)
> >  )
> >
> > -DEFINE_EVENT(xe_vma, xe_vma_flush,
> > -            TP_PROTO(struct xe_vma *vma),
> > -            TP_ARGS(vma)
> > -);
> > -
> >  DEFINE_EVENT(xe_vma, xe_vma_pagefault,
> >              TP_PROTO(struct xe_vma *vma),
> >              TP_ARGS(vma)
> > --
> > 2.47.3
> >