Date: Thu, 16 Jul 2015 08:08:49 -0600 From: Ian Lepore <ian@freebsd.org> To: Mark Murray <markm@FreeBSD.org> Cc: Adrian Chadd <adrian.chadd@gmail.com>, "src-committers@freebsd.org" <src-committers@freebsd.org>, "svn-src-all@freebsd.org" <svn-src-all@freebsd.org>, "svn-src-head@freebsd.org" <svn-src-head@freebsd.org> Subject: Re: svn commit: r284959 - in head: . share/man/man4 share/man/man9 sys/conf sys/dev/glxsb sys/dev/hifn sys/dev/random sys/dev/rndtest sys/dev/safe sys/dev/syscons sys/dev/ubsec sys/dev/virtio/random sy... Message-ID: <1437055729.1334.359.camel@freebsd.org> In-Reply-To: <6FF99E82-AE79-4112-8EB9-DC35B75F498D@FreeBSD.org> References: <201506301700.t5UH0jPq001498@svn.freebsd.org> <CAJ-VmomjDvkH7R-fhSbjFwj2XzNt4Z67aSKt-LRvvRTeVi2EPQ@mail.gmail.com> <6FF99E82-AE79-4112-8EB9-DC35B75F498D@FreeBSD.org>
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On Thu, 2015-07-16 at 06:39 +0100, Mark Murray wrote: > > On 15 Jul 2015, at 23:43, Adrian Chadd <adrian.chadd@gmail.com> wrote: > > > >> - Add harvesting of slab allocator events. This needs to be checked for > >> weighing down the allocator code. > > > > Hi, > > > > Is this really doing it upon every one of those events? eg, for each > > mbuf alloc through UMA? > > Only if you turn it on! > > M > In random_harvestq_init() I see harvest_context.hc_source_mask = RANDOM_HARVEST_EVERYTHING_MASK; and #define RANDOM_HARVEST_EVERYTHING_MASK ((1 << (RANDOM_ENVIRONMENTAL_END + 1)) - 1) So doesn't that include the RANDOM_FAST flag that controls harvesting during every UMA alloc and free call? And that harvesting appears to be anything but fast, at least at a glance... it looks like it passes the entire struct uma_zone to the jenkins hash function... is there really useful entropy in all the data in that struct? -- Ian
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