Date: Mon, 9 Jan 2012 16:46:23 +0200 From: Kostik Belousov <kostikbel@gmail.com> To: Bruce Evans <brde@optusnet.com.au> Cc: jilles@FreeBSD.org, Attilio Rao <attilio@FreeBSD.org>, flo@FreeBSD.org, Giovanni Trematerra <gianni@FreeBSD.org>, freebsd-arch@FreeBSD.org Subject: Re: pipe/fifo code merged. Message-ID: <20120109144623.GW31224@deviant.kiev.zoral.com.ua> In-Reply-To: <20120110005155.S2378@besplex.bde.org> References: <CACfq093o9iVZKxCj58OR2hpCLDYTUTdxg_re_bEMYn2SrNrLCQ@mail.gmail.com> <20120110005155.S2378@besplex.bde.org>
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--6cExhHXXDEBW2NKZ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Tue, Jan 10, 2012 at 01:34:23AM +1100, Bruce Evans wrote: > For the socket layer, there is the ZERO_COPY_SOCKETS options. This > gives optimizations related to the ones for pipes. I have no experience > with it. It seems to be only for hardware sockets. It is apparently > not very popular or well maintained, since it isn't an any GENERIC. It is known to be (very) broken with regard to the vnode-backed mappings. AFAIR, after the COW kicks in, buffer code operates on the wrong page. In the best case, it results in the kernel panic, in the worst, the user data is corrupted. --6cExhHXXDEBW2NKZ Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (FreeBSD) iEYEARECAAYFAk8K/b8ACgkQC3+MBN1Mb4g28ACeJFiMeJoj0HrHf0AZVpc0xybn yG4An2BspEMgFbnA6JoSfEMU0XZbkSv7 =ek7t -----END PGP SIGNATURE----- --6cExhHXXDEBW2NKZ--
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