Date: Tue, 30 Mar 2004 16:00:03 -0500 (EST) From: Robert Watson <rwatson@freebsd.org> To: Dag-Erling =?iso-8859-1?q?Sm=F8rgrav?= <des@des.no> Cc: current@freebsd.org Subject: Re: performance of jailed processes Message-ID: <Pine.NEB.3.96L.1040330155837.93169O-100000@fledge.watson.org> In-Reply-To: <xzpbrmerrbi.fsf@dwp.des.no>
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On Tue, 30 Mar 2004, Dag-Erling Smørgrav wrote: > Robert Watson <rwatson@freebsd.org> writes: > > Somewhat more painful suggestion, but could you generate ktraces against a > > mysql client doing the query inside and out of jail, then using whatever > > flag sets relative timestamps on kdump, diff the two and see where the > > substantial differences begin? > > I'll give it a shot tomorrow. I've had quite a bit of luck resolving mysql problems in jail using this approach, fwiw, during some confusion relating to UNIX domain sockets at an ISP I provide some help to. > > 13 seconds is too long for most of the potential things I have in mind... > > although the query only returns one row, it's a pretty big row, so 13 > seconds could be explained by per-syscall or per-packet overhead. Theory goes that there should be no per-read/write system call change in behavior for TCP with jail. Jail impacts bind/connect, and potentially each I/O on UDP for an unbound socket using sendto. Robert N M Watson FreeBSD Core Team, TrustedBSD Projects robert@fledge.watson.org Senior Research Scientist, McAfee Research
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