Date: Fri, 1 Jun 2012 09:03:38 -0700 From: mdf@FreeBSD.org To: Bruce Evans <brde@optusnet.com.au> Cc: svn-src-head@freebsd.org, Eitan Adler <eadler@freebsd.org>, svn-src-all@freebsd.org, Sergey Kandaurov <pluknet@freebsd.org>, src-committers@freebsd.org Subject: Re: svn commit: r236380 - head/sys/vm Message-ID: <CAMBSHm9O5Z5HLX-FaOT=e_4ot2JHiZD2mRuXLCgSm=68SRLA2g@mail.gmail.com> In-Reply-To: <20120601175403.H1865@besplex.bde.org> References: <201206010442.q514gqqv084148@svn.freebsd.org> <CAE-mSOK=qyKbTwnKx_y5VmDNdYJG_K7R4j6565hWy09gEu_wZQ@mail.gmail.com> <20120601175403.H1865@besplex.bde.org>
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On Fri, Jun 1, 2012 at 2:14 AM, Bruce Evans <brde@optusnet.com.au> wrote: >>> +SYSCTL_OID(_vm, OID_AUTO, swap_free, >>> CTLTYPE_INT|CTLFLAG_RD|CTLFLAG_MPSAFE, >>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 NULL, 0, sysctl_vm_swap_free, "Q", >>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 "Blocks of free swap storage."); > > > Bug 9 is a style bug. =A0I didn't even know that the raw SYSCTL_OID() cou= ld > be misused like this. =A0The normal SYSCTL_PROC() is identical with > SYSCTL_OID() except it checks that the access flags are not 0. =A0Few or = no > SYSCTL_FOO()s have no access flags, and this is not one. =A0It has rather > excessive access flags (I think CTLFLAG_MPSAFE is unnecessary. I wanted to correct this one point. CTLFLAG_MPSAFE is helpful, because its use prevents kern_sysctl from taking Giant before calling the sysctl handler. It's probably nearing the case, now, that any sysctl *without* CTLFLAG_MPSAFE is incorrect, except perhaps for a few that set/get text strings that don't want to roll their own serialization. Cheers, matthew
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