Hello, On Thu, Jun 15, 2006 at 02:21:56AM +0200, Philip Mucci wrote: > Hi Stefane, > > I'm still catching up on other emails, but I'm often in favor of the > 'simple' approach. I'm sure the LKML folks will have their own opinions, > but the simple fixed number approach seems like the right > compromise...perhaps with a tunable parameter depending on the > architecture and stack size. Also, perhaps we could get more out of it > by doing a software prefetch on the stack buffer...reducing the cold > misses...Honestly, it would be ideal if we could get those structs to > fit in a handful of registers or cache lines... > I checked on i386 and the default kernel stack size is 8KB (2 pages). It can be reduced to 4KB with a compile time option. On IA-64 it is 2 pages as well (32KB), if I recall. Don't know for MIPS, PPC64.
I think I want to try the small stack buffer with a size that depends on the architecture. I'll have that in my next patch and we will get a performance boost for read/write pmc and pmd registers. -- -Stephane _______________________________________________ perfmon mailing list [email protected] http://www.hpl.hp.com/hosted/linux/mail-archives/perfmon/
