Date: Sun, 22 Nov 2015 13:12:54 +0100 From: Oliver Pinter <oliver.pinter@hardenedbsd.org> To: "Simon J. Gerraty" <sjg@juniper.net> Cc: Mark Johnston <markj@freebsd.org>, freebsd-arch@freebsd.org Subject: Re: zero-cost SDT probes Message-ID: <CAPQ4ffs4m%2Bp2uK_7rGgL-G1qmzWLOmfv0rb6WRmJG%2BVA_skXfw@mail.gmail.com> In-Reply-To: <2753.1448173777@chaos> References: <20151122024542.GA44664@wkstn-mjohnston.west.isilon.com> <2753.1448173777@chaos>
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On 11/22/15, Simon J. Gerraty <sjg@juniper.net> wrote: > Mark Johnston <markj@freebsd.org> wrote: >> For the past while I've been experimenting with various ways to >> implement "zero-cost" SDT DTrace probes. Basically, at the moment an SDT >> probe site expands to this: > > Would it be feasible to compile the probes into the kernel > as active calls to a registrar function? > That would eliminate all the complexity of finding PC's > though you'd probably need to pass extra args to convey the point of the > probe? > > It would hurt boot time a little too - each probe point would make a > call to register itself (and get overwritten with nops as a reward) but > very simple? In opBSD I have already a similar mechanism for SMAP: https://github.com/opntr/opBSD/commits/op/gsoc2014/master . > _______________________________________________ > freebsd-arch@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-arch > To unsubscribe, send any mail to "freebsd-arch-unsubscribe@freebsd.org" >
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