Date: Mon, 30 Dec 2013 21:40:34 -0500 From: Mark Johnston <markj@freebsd.org> To: Gleb Smirnoff <glebius@FreeBSD.org> Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, Mike Ma <mikemandarine@gmail.com>, src-committers@freebsd.org Subject: Re: svn commit: r260091 - in head/sys/cddl: contrib/opensolaris/uts/common/dtrace contrib/opensolaris/uts/common/sys dev/dtrace Message-ID: <20131231023952.GA11997@charmander.home> In-Reply-To: <20131230204210.GD71033@FreeBSD.org> References: <201312301737.rBUHbW3I035088@svn.freebsd.org> <20131230204210.GD71033@FreeBSD.org>
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On Tue, Dec 31, 2013 at 12:42:10AM +0400, Gleb Smirnoff wrote: > On Mon, Dec 30, 2013 at 05:37:32PM +0000, Mark Johnston wrote: > M> Author: markj > M> Date: Mon Dec 30 17:37:32 2013 > M> New Revision: 260091 > M> URL: http://svnweb.freebsd.org/changeset/base/260091 > M> > M> Log: > M> Now that vmem(9) is available, use vmem arenas to allocate probe and > M> aggregation IDs, as is done in the upstream illumos code. This still > M> requires some FreeBSD-specific code, as our vmem API is not identical to the > M> one in illumos. > M> > M> Submitted by: Mike Ma <mikemandarine@gmail.com> > > IMHO, alloc_unr() was lighter and thus better for allocating just IDs. That's true; I committed the change since it helps keep our code similar to upstream and, as Pedro notes, it was a long-standing todo item on the wiki. After doing some testing, it looks like vmem is a bit slower: process startup is on the order of tenths of milliseconds longer with this change, for executables containing one USDT probe (since such probes are allocated during process startup). So probably the right thing to do is revert this change. It doesn't actually reduce the upstream diff as much as I'd hoped, anyway. Thanks, -Mark
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