Date: Wed, 25 Mar 2015 14:14:33 +0300 From: Gleb Smirnoff <glebius@FreeBSD.org> To: Hans Petter Selasky <hps@selasky.org> Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r280495 - head/sys/kern Message-ID: <20150325111433.GT64665@FreeBSD.org> In-Reply-To: <551296C6.9070402@selasky.org> References: <201503250855.t2P8tZFp038467@svn.freebsd.org> <20150325105409.GS64665@FreeBSD.org> <551296C6.9070402@selasky.org>
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On Wed, Mar 25, 2015 at 12:06:46PM +0100, Hans Petter Selasky wrote: H> On 03/25/15 11:54, Gleb Smirnoff wrote: H> > On Wed, Mar 25, 2015 at 08:55:35AM +0000, Hans Petter Selasky wrote: H> > H> Author: hselasky H> > H> Date: Wed Mar 25 08:55:34 2015 H> > H> New Revision: 280495 H> > H> URL: https://svnweb.freebsd.org/changeset/base/280495 H> > H> H> > H> Log: H> > H> Implement a simple OID number garbage collector. Given the increasing H> > H> number of dynamically created and destroyed SYSCTLs during runtime it H> > H> is very likely that the current new OID number limit of 0x7fffffff can H> > H> be reached. Especially if dynamic OID creation and destruction results H> > H> from automatic tests. Additional changes: H> > H> H> > H> - Optimize the typical use case by decrementing the next automatic OID H> > H> sequence number instead of incrementing it. This saves searching time H> > H> when inserting new OIDs into a fresh parent OID node. H> > H> H> > H> - Add simple check for duplicate non-automatic OID numbers. H> > H> > Why didn't you use alloc_unr(9) for that? H> > H> H> Hi Gleb, H> H> I thought about using alloc_unr(). The problem is that sysctls have no H> clear concept of freeing. For example in some existing code sysctl are H> unregistered and registered again assuming that the oid_number will be H> preserved. I didn't want touch those parts. Also, hence we are already H> traversing a list to insert an SYSCTL object in an ordered fashion, the H> benefit of alloc_unr() is not that big. What do you think? Is it possible to split the space into two halves: one for static OIDs and other for dynamic ones? The latter allocated via alloc_unr? -- Totus tuus, Glebius.
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