Date: Mon, 10 Dec 2001 19:02:48 -0800 (PST) From: Luigi Rizzo <luigi@FreeBSD.org> To: cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/pci if_dc.c Message-ID: <200112110302.fBB32mU93520@freefall.freebsd.org>
next in thread | raw e-mail | index | archive | help
luigi 2001/12/10 19:02:48 PST
Modified files: (Branch: RELENG_4)
sys/pci if_dc.c
Log:
MFC (done now because the code is slightly different from the one
in -current): avoid an unnecessary copy when the packet is already
in a single buffer.
With this one-line patch, a 750MHz box goes from 128kpps to 148kpps
(full wire speed) even with NICs that require packets in a single mbuf.
Trivia: the 21143, which can handle multiple buffers, seems to
introduce extra delay between packets when they are split over
multiple tx descriptors. So if you are in this situation and have
CPU cycles to burn, doing the copy is the only way to achieve wire
speed (short of arranging tx descriptors as an array instead of a
linked list).
Revision Changes Path
1.9.2.30 +3 -1 src/sys/pci/if_dc.c
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe cvs-all" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200112110302.fBB32mU93520>