On Tue, Nov 27, 2007 at 03:56:53PM +0100, Geert Uytterhoeven wrote: > On Wed, 21 Nov 2007, Geert Uytterhoeven wrote: > > On Tue, 20 Nov 2007, Kumar Gala wrote: > > > On Nov 20, 2007, at 11:54 AM, Scott Wood wrote: > > > > On Mon, Nov 19, 2007 at 09:36:57PM -0600, Kumar Gala wrote: > > > >> isel (Integer Select) is a new user space instruction in the > > > >> PowerISA 2.04 spec. Not all processors implement it so lets emulate > > > >> to ensure code built with isel will run everywhere. > > > > > > > > Given that the instruction is meant to be a performance enhancement, > > > > we should probably warn the first few times it's emulated, so the user > > > > knows they should change their toolchain setup if possible. > > > > > > The same is true of mcrxr, popcntb, and possibly string ld/st. > > > > > > Feel free to submit a patch that warns about their usage. > > > > Something like this? > > New version below. > > Do we want it in sysfs? Or should we use debugfs instead?
I like this, and I'd say it's useful to have in sysfs. Few production systems enable debugfs, and this is something that could be useful to have access to there. > Subject: powerpc: Keep track of emulated instructions > > From: Geert Uytterhoeven <[EMAIL PROTECTED]> > > powerpc: Keep track of emulated instructions > > Counters for the various classes of emulated instructions are available under > /sys/devices/system/cpu/cpu*/emulated/. > Optionally, rate-limited warnings can be printed to the console when > instructions are emulated. > > Signed-off-by: Geert Uytterhoeven <[EMAIL PROTECTED]> > --- > arch/powerpc/Kconfig.debug | 10 ++++++ > arch/powerpc/kernel/align.c | 17 ++++++++-- > arch/powerpc/kernel/sysfs.c | 64 > ++++++++++++++++++++++++++++++++++++++++- > arch/powerpc/kernel/traps.c | 17 +++++++++- > include/asm-powerpc/emulator.h | 60 ++++++++++++++++++++++++++++++++++++++ This name stood out as being a bit too generic, emulator could mean system support for running under some sort of emulator as well. How about emulated_ops.h? > +config DEBUG_WARN_EMULATED > + bool "Warn if emulated instructions are used" > + depends on DEBUG_KERNEL && SYSFS > + help > + This option will cause messages to be printed if an instruction is > + emulated. > + Counters for emulated instruction usages are always available under > + /sys/devices/system/cpu/cpu*/emulated/, irrespective of the state > + of this option. How about making it a sysctl instead, so it can be flipped at runtime (but default off)? -Olof _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
