Date: Thu, 2 Jun 2016 16:28:24 +0200 From: Roger Pau =?iso-8859-1?Q?Monn=E9?= <royger@FreeBSD.org> To: Hans Petter Selasky <hps@selasky.org> Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r301197 - head/sys/dev/xen/netfront Message-ID: <20160602142824.m6d24n2rx3i2kclt@mac> In-Reply-To: <c8ef340a-e3d3-af3e-d45c-eedf4183750b@selasky.org> References: <201606021114.u52BEQqB047172@repo.freebsd.org> <2c81e44d-65de-10f0-8837-f23896855150@selasky.org> <20160602125422.gmdsueoeu5fiiec5@mac> <c8ef340a-e3d3-af3e-d45c-eedf4183750b@selasky.org>
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On Thu, Jun 02, 2016 at 03:01:03PM +0200, Hans Petter Selasky wrote: > On 06/02/16 14:54, Roger Pau Monné wrote: > > On Thu, Jun 02, 2016 at 01:19:56PM +0200, Hans Petter Selasky wrote: > > > On 06/02/16 13:14, Roger Pau Monné wrote: > > > > + callout_reset(&rxq->rx_refill, hz/10, xn_alloc_rx_buffers_callout, > > > > + rxq); > > > > > > Maybe use callout_reset_curcpu() to take advantage of callout's SMP > > > capabilities ? > > > > Yes, that's fine. But what's the benefit of it? I don't really care whether > > the callout is run on the current CPU or not. Is callout_reset_curcpu > > cheaper than callout_reset? > > > > Hi, > > It is maybe not cheaper, but it will distribute the load of the > xn_alloc_rx_buffers_callout() callback, to the current CPU calling > callout_reset_curcpu(). Else xn_alloc_rx_buffers_callout() will always be > called from callback thread zero. Thanks for the clarification. I did get the impression that callout_reset already distributed the callbacks across the number of available CPUs, maybe the man page should be expanded to explain this? I've committed the change as r301204. Roger.
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