Date: Tue, 15 Jul 2014 07:33:57 -0700 From: Adrian Chadd <adrian@freebsd.org> To: Slawa Olhovchenkov <slw@zxy.spb.ru> Cc: "freebsd-arch@freebsd.org" <freebsd-arch@freebsd.org> Subject: Re: UDP/TCP versus IP frames - subtle out of order packets with hardware hashing Message-ID: <CAJ-VmomTL=fZnjSTBT6-3KNA0DOqNEefoXNwFipade81dSBK5Q@mail.gmail.com> In-Reply-To: <20140715113319.GA96254@zxy.spb.ru> References: <CAJ-VmomUNJ23CHLLX2qryAuE2XQyBmo30du3MuRnobs%2BwEkguA@mail.gmail.com> <53C4EE00.5090705@gmail.com> <20140715093125.GA89128@zxy.spb.ru> <53C507F2.2090604@gmail.com> <20140715113319.GA96254@zxy.spb.ru>
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On 15 July 2014 04:33, Slawa Olhovchenkov <slw@zxy.spb.ru> wrote: > On Tue, Jul 15, 2014 at 03:22:34PM +0430, Hooman Fazaeli wrote: > >> On 7/15/2014 2:01 PM, Slawa Olhovchenkov wrote: >> > On Tue, Jul 15, 2014 at 01:31:52PM +0430, Hooman Fazaeli wrote: >> > >> >> Doesn't the problem applies to TCP too? >> >> TCP may be fragmented too but is less likely because of MSS. >> > Don't forget GRE, IPIP, ESP and AH! >> > >> These protocols don't use port numbers and the RSS hash is computed based on the >> (srcip,dstip) tuple, so the problem does not apply to them. > > And all flows go to one queue? Bad. All the packets between two IP addresses for non-TCP, non-UDP get hashed to the same CPU core, yes. If you have 1000 IP tunnels to different end-hosts, they'll be on different CPUs. -a
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