From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 13088 invoked by alias); 1 May 2012 21:30:37 -0000 Received: (qmail 13080 invoked by uid 22791); 1 May 2012 21:30:36 -0000 X-SWARE-Spam-Status: No, hits=-5.9 required=5.0 tests=AWL,BAYES_00,KHOP_RCVD_UNTRUST,RCVD_IN_DNSWL_HI,RCVD_IN_HOSTKARMA_W,SPF_HELO_PASS,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 01 May 2012 21:30:21 +0000 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q41LUK7h023855 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Tue, 1 May 2012 17:30:20 -0400 Received: from fche.csb (vpn-8-204.rdu.redhat.com [10.11.8.204]) by int-mx01.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id q41LUKx3025753; Tue, 1 May 2012 17:30:20 -0400 Received: by fche.csb (Postfix, from userid 2569) id B97C05813A; Tue, 1 May 2012 17:30:19 -0400 (EDT) To: "Turgis, Frederic" Cc: "systemtap@sourceware.org" Subject: Re: Tune reader_thread poll timeout value References: <28BE1A38672C8B4481BB423D0FD1F22E18F55BE1@DNCE04.ent.ti.com> From: fche@redhat.com (Frank Ch. Eigler) Date: Tue, 01 May 2012 21:30:00 -0000 In-Reply-To: <28BE1A38672C8B4481BB423D0FD1F22E18F55BE1@DNCE04.ent.ti.com> (Frederic Turgis's message of "Tue, 1 May 2012 20:09:49 +0000") Message-ID: User-Agent: Gnus/5.1008 (Gnus v5.10.8) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Mailing-List: contact systemtap-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: systemtap-owner@sourceware.org X-SW-Source: 2012-q2/txt/msg00092.txt.bz2 f-turgis wrote: > [...] The last non tunable or small duration source of wake-up is > "reader_thread" ppoll timeout value, every 200ms. We compile > systemtap with a value of 2s or more for our daily use. Do you notice any adverse effects from this? For an output-heavy script for example, does this cause more out-of-buffer conditions? > So I am proposing to introduce tunables below as an example. Don't > know if I should have correlated s and ns, also don't know if this > should also be applied to relay_old.c. Please tell me if this is an > acceptable change: Looks OK, though I would rather have just one configurable like STP_RELAY_TIMEOUT_MS from which the .tv_sec and .tv_nsec values are calculated. (Ideally, a baby PLL could regulate this timeout dynamically, adjusted with the actual ebb and flow of tracing traffic.) - FChE