Date: Thu, 5 Aug 1999 07:42:17 +1000 From: Peter Jeremy <jeremyp@gsmx07.alcatel.com.au> To: hackers@FreeBSD.ORG Cc: des@flood.ping.uio.no Subject: Re: Results of investigating optimizing calloc()... Message-ID: <99Aug5.072253est.40331@border.alcanet.com.au>
next in thread | raw e-mail | index | archive | help
Dag-Erling Smorgrav <des@flood.ping.uio.no> wrote: >Which reminds me - has anyone thought of using DMA for zeroing pages, This sounds reasonable. Some DMA engines support filling regions and memory-memory copies, but I'm not sure about what can be done with the DMA engine(s) in PCs. > The idea is to keep a chunk of zeroes on disk and DMA it into memory Have you looked at disk latencies recently? A modern CPU could zero- fill a decent fraction of its RAM in the time taken to fetch a page of zeroes from the platter. And if it was accessed frequently enough to keep the zeroed page in disk cache, you've just moved the bottleneck into that disk controller (and you've reduced the effective size of the disk's cache by a page). Peter To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?99Aug5.072253est.40331>