Date: Fri, 10 Dec 2004 23:10:00 -0800 From: Alfred Perlstein <alfred@freebsd.org> To: "Christian S.J. Peron" <csjp@FreeBSD.org> Cc: cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/netinet ip_fw2.c Message-ID: <20041211070959.GT20783@elvis.mu.org> In-Reply-To: <200412100217.iBA2HI2L008474@repoman.freebsd.org> References: <200412100217.iBA2HI2L008474@repoman.freebsd.org>
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* Christian S.J. Peron <csjp@FreeBSD.org> [041209 18:17] wrote:
> csjp 2004-12-10 02:17:18 UTC
>
> It should be noted that this locking mechanism does not guarantee
> fairness between read and write locks, and that it will favor
> firewall chain readers over writers. This seemed acceptable since
> write operations to firewall chains protected by this lock tend to
> be less frequent than reads.
>
> Reviewed by: andre, rwatson
> Tested by: myself, seanc
> Silence on: ipfw@
> MFC after: 1 month
>
> Revision Changes Path
> 1.85 +69 -29 src/sys/netinet/ip_fw2.c
The code I see doesn't appear to work right.
Can you switch it using sx lock? see the sx_xlock(9) API.
Specifically:
static __inline void
IPFW_RLOCK(struct ip_fw_chain *chain)
{
mtx_lock(&chain->mtx);
chain->busy_count++;
mtx_unlock(&chain->mtx);
}
What if there already is an WLOCK? It doesn't block the
reader.
--
- Alfred Perlstein
- Research Engineering Development Inc.
- email: bright@mu.org cell: 408-480-4684
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