This is the mail archive of the
systemtap@sourceware.org
mailing list for the systemtap project.
Re: Hashtable
- From: fche at redhat dot com (Frank Ch. Eigler)
- To: Arkady <arkady dot miasnikov at gmail dot com>
- Cc: David Smith <dsmith at redhat dot com>, systemtap at sourceware dot org
- Date: Sun, 16 Jul 2017 12:09:29 -0400
- Subject: Re: Hashtable
- Authentication-results: sourceware.org; auth=none
- Authentication-results: ext-mx06.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com
- Authentication-results: ext-mx06.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=fche at redhat dot com
- Dkim-filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 05315369C4
- Dmarc-filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 05315369C4
- References: <CANA-60rYyDZEn7HfETX4HiGnJ1Jc90Be-Yd-1dJp1TEZeJPPcw@mail.gmail.com> <CAKFOr-YvT+w9Ak4f3_N-EidPyM7V5QZrjGcmN=owtYLNBotuXQ@mail.gmail.com> <CANA-60obFDOGZFR9zeC7VKYUZ5L5yyu1iJhdTx6rwyZFSvUvwA@mail.gmail.com>
arkady.miasnikov wrote:
> [...]
> I am playing with something I call "STAP bypass" - allow to register a
> pure C implementation of a probe. This gives about 1% gain part of
> which comes from removing calls to _stp_print_flush(). A define symbol
> like STP_TRACE_OFF would be nice. [...]
That _stp_print_flush() bit could be elided by analysis of the staptree
associated with the probe; if no print*s are found there (or any
function transitively called), then no need to flush. (For embedded-C
functions, we could add a /* print */ pragma to handle that in the
analysis.)
- FChE