Date: Sat, 12 Nov 2005 16:44:18 +0900 From: Pyun YongHyeon <pyunyh@gmail.com> To: Peter Jeremy <PeterJeremy@optushome.com.au> Cc: freebsd-hackers@freebsd.org Subject: Re: poor fdc(4) performance Message-ID: <20051112074418.GE18405@rndsoft.co.kr> In-Reply-To: <20051112073711.GE39882@cirb503493.alcatel.com.au> References: <20051112071815.GD18405@rndsoft.co.kr> <20051112073711.GE39882@cirb503493.alcatel.com.au>
next in thread | previous in thread | raw e-mail | index | archive | help
On Sat, Nov 12, 2005 at 06:37:11PM +1100, Peter Jeremy wrote: > On Sat, 2005-Nov-12 16:18:15 +0900, Pyun YongHyeon wrote: > >I encountered a P3 SMP system that shows poor fdc(4) performance. > >But when I use larger block size, say 36b, it seems it works > >as expected. > > 36b is one track. My suspicion is that the system isn't fast enough > to read sequential blocks, one at a time, so you're forced to wait > a complete revolution (plus a bit) for each block you read. > Yes, it could be. But I think the machine is fast enough to read sequential blocks. Part of dmesg shows: CPU: Intel Pentium III (800.03-MHz 686-class CPU) Origin = "GenuineIntel" Id = 0x686 Stepping = 6 Features=0x387fbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,P AT,PSE36,PN,MMX,FXSR,SSE> real memory = 402587648 (383 MB) avail memory = 384385024 (366 MB) FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs cpu0 (BSP): APIC ID: 0 cpu1 (AP): APIC ID: 1 And I think I got much better result on slow i386 machines except this one. -- Regards, Pyun YongHyeon
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20051112074418.GE18405>