Re: [PATCH RESEND] trace_uprobe: support reference counter in fd-based uprobe

From: Peter Zijlstra
Date: Fri Sep 28 2018 - 03:52:36 EST


On Fri, Sep 28, 2018 at 07:23:20AM +0000, Song Liu wrote:
> Hi Peter,
> > #ifdef CONFIG_UPROBE_EVENTS
> > +PMU_FORMAT_ATTR(ref_ctr_offset, "config:63-24");
>
> I guess you meant this part? This is for uprobe only, so I put
> it here.

Ah,.. right you are.

You seem to have the bitfield backwards, does that mean we should write
the bits in backwards too? Seems a tad loopy if you ask me.

Did you instead mean: "config:24-63" ? Also, why 40 bits? 32 seems like
a much more natural amount.