Date: Mon, 30 Jul 2012 14:45:45 -0400 From: John Baldwin <jhb@freebsd.org> To: Luigi Rizzo <luigi@freebsd.org> Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r238765 - head/sys/dev/e1000 Message-ID: <201207301445.45210.jhb@freebsd.org> In-Reply-To: <201207251128.q6PBSFlt052575@svn.freebsd.org> References: <201207251128.q6PBSFlt052575@svn.freebsd.org>
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On Wednesday, July 25, 2012 7:28:15 am Luigi Rizzo wrote: > Author: luigi > Date: Wed Jul 25 11:28:15 2012 > New Revision: 238765 > URL: http://svn.freebsd.org/changeset/base/238765 > > Log: > Use legacy interrupts as a default. This gives up to 10% speedup > when used in qemu (and this driver is for non-PCIe cards, > so probably its largest use is in virtualized environments). > > Approved by: Jack Vogel > MFC after: 3 days Why not make this a tunable or some such? You could even have it only use the legacy handler under qemu easily enough. There's no reason this has to be a compile-time option. This is almost certainly slower on real hardware where this is important to work around dubious Intel Host-PCI bridges that result in aliased USB interrupts for every em(4) interrupt. -- John Baldwin
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