Date: Thu, 12 May 2005 07:18:27 -0700 (PDT) From: Mohan Srinivasan <mohan_srinivasan@yahoo.com> To: Daniel Eriksson <daniel_k_eriksson@telia.com>, freebsd-current@FreeBSD.org Cc: 'Paul Saab' <ps@FreeBSD.org> Subject: RE: cvs commit: src/sys/netinet tcp_input.c tcp_output.c tcp_sack.c tcp_var.h Message-ID: <20050512141827.95064.qmail@web80604.mail.yahoo.com> In-Reply-To: 6667
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Thanks. I'll take a look at this. mohan --- Daniel Eriksson <daniel_k_eriksson@telia.com> wrote: > Paul Saab wrote: > > > ps 2005-05-11 21:37:43 UTC > > > > FreeBSD src repository > > > > Modified files: > > sys/netinet tcp_input.c tcp_output.c tcp_sack.c > > tcp_var.h > > Log: > > When looking for the next hole to retransmit from the scoreboard, > > or to compute the total retransmitted bytes in this sack recovery > > episode, the scoreboard is traversed. While in sack recovery, this > > traversal occurs on every call to tcp_output(), every dupack and > > every partial ack. The scoreboard could potentially get quite large, > > making this traversal expensive. > > > > This change optimizes this by storing hints (for the next hole to > > retransmit and the total retransmitted bytes in this sack recovery > > episode) reducing the complexity to find these values from O(n) to > > constant time. > > > > The debug code that sanity checks the hints against the computed > > value will be removed eventually. > > After upgrading one of my servers this morning (dual Athlon MP) I'm getting > a fair amount of these on the console: > > tcp_sack_output: Computed sack hole not the same as cached value > > So far I have ~50 such lines in the log after ~3 hours of uptime. No users > have reported any problems though. > > /Daniel Eriksson > > > _______________________________________________ > freebsd-current@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-current > To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.org" >
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