Re: Tooltips GC overhead

[martin rudalics <rudalics@gmx.at>]

 >> There are one call of `copy-sequence', two calls of `stringp', three of
 >> `setf', one of `propertize' and one of `selected-frame'.  Together these
 >> would allocate some 20 million bytes?
 >
 > That's what it's saying, yes.
 >
 >> OTOH the `copy-sequence', `face-attribute' and `alist-get' calls get
 >> nowhere listed.
 >
 > copy-sequence and propertize are in C.  Either can easily allocate millions of bytes.

Just that `copy-sequence' makes a copy of a three elements alist.  And
`propertize' usually propertizes a text of a at most hundred characters
here.  If that function were that expensive, Emcas would be stuck most
of the time.

 > Perhaps face-attribute doesn't allocate storage; that would explain its not being listed.

This would make things even more mysterious.

 > alist-get is in a call to the setf macro and you may need to
 > investigate what setf is really doing.  One way to look into that is
 > to disassemble the byte code (type "M-x disassemble RET tooltip-show
 > RET") and see what it does.

I suppose running `tooltip-show' interpreted might be the easier way.

In any case, neither the profiler nor tooltips appear usable in their
current implementation.

martin