Date: Fri, 4 Nov 2005 12:08:12 +0200 From: Ivo Vachkov <ivo.vachkov@gmail.com> To: kamal kc <kamal_ckk@yahoo.com>, freebsd-net@freebsd.org Subject: Re: allocating 14KB memory per packet compression/decompression results in vm_fault Message-ID: <f85d6aa70511040208w6659500di@mail.gmail.com> In-Reply-To: <20051104065630.9592.qmail@web35704.mail.mud.yahoo.com> References: <20051103145729.GA2088@flame.pc> <20051104065630.9592.qmail@web35704.mail.mud.yahoo.com>
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2005/11/4, kamal kc <kamal_ckk@yahoo.com>: > > > > for my compression/decompression i use string > > tables and temporary > > > buffers which take about 14KB of memory per > > packet. > > > > If you're allocating 14 KB of data just to send > > (approximately) 1.4 KB > > and then you throw away the 14 KB immediately, it > > sounds terrible. > > yes that's true. > > since i am using the adaptive LZW > compression scheme it requires construction of string > table for compression/decompression. So an ip packet > of size 1500 bytes requires a table of size (4KB + > 4KB + 2KB =3D12KB). > > further still i copy the ip packet > data in another data buffer (about 1.4KB) and > then compress it. > > So all this adds up to about 14KB. > > Right now i can't do with less than 14KB. > > as i said before the compression/decompression works > fine. but soon the kernel would panic with one > of the vm_fault: error message. > > what would be the best possible way to > allocate/deallocate 14KB memory per packet without > causing vm_faults ?? > > is there anything i am missing ?? 1. do you free all buffers you're using after sending the packet (probably in if_output()/ether_output()) ? 2. you could try to allocate the buffers during system startup and reuse th= em. > thanks > > kamal > > > > > > > > > > > > > > __________________________________ > Yahoo! Mail - PC Magazine Editors' Choice 2005 > http://mail.yahoo.com > _______________________________________________ > freebsd-net@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org" > -- "UNIX is basically a simple operating system, but you have to be a genius to understand the simplicity." Dennis Ritchie
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