Hi Jeff On Wed, 25 Aug 2004, Jeff Ai wrote: > Hi guys, > Recently i upgraded from FC1 to FC2. My machine's got a P4 2.8 HT, > kernel is 2.6.8-1.521smp , lilo.conf has acpismp=force. > > i found something quite strange. > 1. cat /proc/cupinfo shows there are 2 CPUs, which is what i expected. > 2. top shows only CPU. I remember with FC1 2.4.*smp kernel, i could see > 2 CPUs in "top". > 3. I am not noticing a dramatic change in performance, so i am not sure > if HT is actually working on my machine. > > is there anything missing? > > cheers > > J Ai > -- > SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ > Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Just using SMP kernels is not enough to get the full advantage of HTing. The problem is that the second CPU is a virtual CPU and the SMP code does not recognise it properly and will in some cases starve it from being scheduled, thus you end up with a UNI processor system. Looking at the FC2 release notes they are using the 2.6 kernel though you will need to check to see if they have enabled symmetric multi- threading(SMT) when building the the kernel. SMT in general has not quite matured yet with development still being done today in the latest kernel releases. If you would like to take full advantage of SMT I suggest you keep up to date with the latest kernels and build your own. That said I am am using a HT processor with a SMT kernel 2.6.7 and do see improvements in build times using the -j option with make. There are however other issues with 2.6.x that you may be seeing. Many users are reporting that there desktop is sluggish in response times, ripping music sometimes fails or that the machine they are running goes into swap hell (whenever you start a process it takes longer than normal to load and there is a lot of disk activity). If you are seeing any of these symptoms I suggest you go to lkml.org and do a search on your problem, there will be an answer. -------------------------------------------------- Darren Williams <dsw AT gelato.unsw.edu.au> [EMAIL PROTECTED] <www.gelato.unsw.edu.au> -------------------------------------------------- -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
