Re: Error in x86 CPU capabilities starting with test5/6

2000-11-19 Thread Albert D. Cahalan
> As about the broken calling conventions of the IA32 ABI, I think it > doesn't worth to break the binary compatibility at this late stage. We are not at any late stage. The new 64-bit PC processors might be accepted about as well as Microchannel and EISA were accepted. Crummy old 32-bit

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-19 Thread Albert D. Cahalan
As about the broken calling conventions of the IA32 ABI, I think it doesn't worth to break the binary compatibility at this late stage. We are not at any late stage. The new 64-bit PC processors might be accepted about as well as Microchannel and EISA were accepted. Crummy old 32-bit

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-18 Thread Christoph Rohland
Andrea Arcangeli <[EMAIL PROTECTED]> writes: > On Fri, Nov 17, 2000 at 05:06:49PM +0100, Christoph Rohland wrote: > > Could I get this for i686? :-) > > If we break binary compatibility yes. OK, I'll stick to rdtsc on ix86 Christoph - To unsubscribe from this list: send the line

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-18 Thread Christoph Rohland
Andrea Arcangeli [EMAIL PROTECTED] writes: On Fri, Nov 17, 2000 at 05:06:49PM +0100, Christoph Rohland wrote: Could I get this for i686? :-) If we break binary compatibility yes. OK, I'll stick to rdtsc on ix86 Christoph - To unsubscribe from this list: send the line

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Andrea Arcangeli
On Fri, Nov 17, 2000 at 05:06:49PM +0100, Christoph Rohland wrote: > Could I get this for i686? :-) If we break binary compatibility yes. I mean: new glibc binaries wouldn't run anymore on older kernels. Also new static binaries wouldn't run anymore on older kernels. At least if we don't

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Christoph Rohland
Hi Andrea, On Fri, 17 Nov 2000, Andrea Arcangeli wrote: > So as worse you'll have to wait x86-64 to get that lightweight > vgettimeofday. Could I get this for i686? :-) Greetings Christoph - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Andrea Arcangeli
On Fri, Nov 17, 2000 at 01:51:11PM +0100, Christoph Rohland wrote: > gettimeofday is _way_ to slow for a lot of every day uses. So > applications will use rdtsc until we have some really fast > (non-syscall) way to have high resolution time diffs. During the x86-64 design I made sure that in

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Alan Cox
> > I thought Linux kernel does synchronize them on boot? So, you are > > saying I cannot rely on this being 100% correct? > > Yes, it does so far. And if we cannot assume this to be correct in the > microsecond scale on smp machines with homogenous non-powersaving cpus > we will loose on some

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Christoph Rohland
Hi Tigran, On Fri, 17 Nov 2000, Tigran Aivazian wrote: > On Fri, 17 Nov 2000, Andi Kleen wrote: >> [of course rdtsc only works properly on UP or with bind_cpu()] > > I thought Linux kernel does synchronize them on boot? So, you are > saying I cannot rely on this being 100% correct? Yes, it

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Arjan van de Ven
In article <[EMAIL PROTECTED]> you wrote: > Andi Kleen wrote: >> No it would not. Often you want cycle accurate couting for profiling >> purposes. > Isn't that why /dev/cpu/%d/msr exists? This is root only though.. (Yes, you can crash AMD boxes by reading MSR's) Greetings, Arjan van de

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Andi Kleen
On Fri, Nov 17, 2000 at 08:40:27AM -0500, Jeff Garzik wrote: > Andi Kleen wrote: > > No it would not. Often you want cycle accurate couting for profiling > > purposes. > > Isn't that why /dev/cpu/%d/msr exists? Requires either root privileges or is a big security hole. [of course rdtsc only

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Jeff Garzik
Andi Kleen wrote: > No it would not. Often you want cycle accurate couting for profiling > purposes. Isn't that why /dev/cpu/%d/msr exists? -- Jeff Garzik | Building 1024 | The chief enemy of creativity is "good" sense MandrakeSoft| -- Picasso - To

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Mikael Pettersson
Hmm, my CPUID vs /proc/cpuinfo comment seemed somewhat controversial. Tigran Aivazian wrote: > Arguably, it is always better to parse /proc/cpuinfo instead of executing > CPUID directly (think PCI -- drivers should _NOT_ get their irq/io/etc > values from config space directly but only what

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Andi Kleen
On Fri, Nov 17, 2000 at 02:21:03PM +0100, Christoph Rohland wrote: > Hi Jeff, > > On Fri, 17 Nov 2000, Jeff Garzik wrote: > > IIRC, this came up a long time ago WRT Apache, which made a lot of > > gettimeofday() calls. Someone (Linus?) proposed the solution of a > > 'magic page' which holds

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Mohammad A. Haque
It used to be.. flags : fpu vme de pse tsc msr pae but now called features It's a simple enough change. Contact me privately if you can't any avifile people to help. Jordan wrote: > > I have been running a plug in for xmms for some time that uses the > aviplay program and

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Christoph Rohland
Hi Jeff, On Fri, 17 Nov 2000, Jeff Garzik wrote: > IIRC, this came up a long time ago WRT Apache, which made a lot of > gettimeofday() calls. Someone (Linus?) proposed the solution of a > 'magic page' which holds information like gettimeofday() stuff, but > could be handled much more rapidly

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Jeff Garzik
Christoph Rohland wrote: > > Hi Alan, > > On Fri, 17 Nov 2000, Alan Cox wrote: > > Even checking the cpuinfo for the TSC should be done with care, and > > its far far better to use gettimeofday unless doing very tiny > > timings (eg for optimising code paths) > > gettimeofday is _way_ to slow

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Christoph Rohland
Hi Alan, On Fri, 17 Nov 2000, Alan Cox wrote: > Even checking the cpuinfo for the TSC should be done with care, and > its far far better to use gettimeofday unless doing very tiny > timings (eg for optimising code paths) gettimeofday is _way_ to slow for a lot of every day uses. So applications

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Andi Kleen
On Fri, Nov 17, 2000 at 01:14:30PM +0100, Jan Niehusmann wrote: > On Fri, Nov 17, 2000 at 01:04:18PM +0100, Andi Kleen wrote: > > The program would be broken if it executed CPUID itself, because it has no way to >guarantee > > that the CPUID is executed on all CPUs the scheduler may later move

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Jan Niehusmann
On Fri, Nov 17, 2000 at 01:04:18PM +0100, Andi Kleen wrote: > The program would be broken if it executed CPUID itself, because it has no way to >guarantee > that the CPUID is executed on all CPUs the scheduler may later move the task too. I wonder what's the right way for an app to ask the

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Alan Cox
> > You have a user-space program which parses /proc/cpuinfo instead of > > executing CPUID itself, so it breaks. > > Arguably, it is always better to parse /proc/cpuinfo instead of executing Actually this is definitively the case. It is not safe to use cpuid to check the availability of

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Andi Kleen
On Fri, Nov 17, 2000 at 12:39:59PM +0100, Mikael Pettersson wrote: > Jordan writes: > > I have been running a plug in for xmms for some time that uses the > > aviplay program and avifile library...then when upgrading to test5/6 I > > start getting this error message when running xmms: > > >

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Tigran Aivazian
On Fri, 17 Nov 2000, Mikael Pettersson wrote: > You have a user-space program which parses /proc/cpuinfo instead of > executing CPUID itself, so it breaks. Hi Mikael, Arguably, it is always better to parse /proc/cpuinfo instead of executing CPUID directly (think PCI -- drivers should _NOT_ get

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Mikael Pettersson
Jordan writes: > I have been running a plug in for xmms for some time that uses the > aviplay program and avifile library...then when upgrading to test5/6 I > start getting this error message when running xmms: > > ERROR: no time-stamp counter found! Quitting. > ... > contents of

Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Jordan
I have been running a plug in for xmms for some time that uses the aviplay program and avifile library...then when upgrading to test5/6 I start getting this error message when running xmms: ERROR: no time-stamp counter found! Quitting. I finally trace it down to my avi plugin and then from

Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Jordan
I have been running a plug in for xmms for some time that uses the aviplay program and avifile library...then when upgrading to test5/6 I start getting this error message when running xmms: ERROR: no time-stamp counter found! Quitting. I finally trace it down to my avi plugin and then from

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Mikael Pettersson
Jordan writes: I have been running a plug in for xmms for some time that uses the aviplay program and avifile library...then when upgrading to test5/6 I start getting this error message when running xmms: ERROR: no time-stamp counter found! Quitting. ... contents of /proc/cpuinfo:

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Tigran Aivazian
On Fri, 17 Nov 2000, Mikael Pettersson wrote: You have a user-space program which parses /proc/cpuinfo instead of executing CPUID itself, so it breaks. Hi Mikael, Arguably, it is always better to parse /proc/cpuinfo instead of executing CPUID directly (think PCI -- drivers should _NOT_ get

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Andi Kleen
On Fri, Nov 17, 2000 at 12:39:59PM +0100, Mikael Pettersson wrote: Jordan writes: I have been running a plug in for xmms for some time that uses the aviplay program and avifile library...then when upgrading to test5/6 I start getting this error message when running xmms: ERROR:

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Alan Cox
You have a user-space program which parses /proc/cpuinfo instead of executing CPUID itself, so it breaks. Arguably, it is always better to parse /proc/cpuinfo instead of executing Actually this is definitively the case. It is not safe to use cpuid to check the availability of RDTSC in

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Jan Niehusmann
On Fri, Nov 17, 2000 at 01:04:18PM +0100, Andi Kleen wrote: The program would be broken if it executed CPUID itself, because it has no way to guarantee that the CPUID is executed on all CPUs the scheduler may later move the task too. I wonder what's the right way for an app to ask the kernel

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Andi Kleen
On Fri, Nov 17, 2000 at 01:14:30PM +0100, Jan Niehusmann wrote: On Fri, Nov 17, 2000 at 01:04:18PM +0100, Andi Kleen wrote: The program would be broken if it executed CPUID itself, because it has no way to guarantee that the CPUID is executed on all CPUs the scheduler may later move the

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Christoph Rohland
Hi Alan, On Fri, 17 Nov 2000, Alan Cox wrote: Even checking the cpuinfo for the TSC should be done with care, and its far far better to use gettimeofday unless doing very tiny timings (eg for optimising code paths) gettimeofday is _way_ to slow for a lot of every day uses. So applications

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Jeff Garzik
Christoph Rohland wrote: Hi Alan, On Fri, 17 Nov 2000, Alan Cox wrote: Even checking the cpuinfo for the TSC should be done with care, and its far far better to use gettimeofday unless doing very tiny timings (eg for optimising code paths) gettimeofday is _way_ to slow for a lot of

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Christoph Rohland
Hi Jeff, On Fri, 17 Nov 2000, Jeff Garzik wrote: IIRC, this came up a long time ago WRT Apache, which made a lot of gettimeofday() calls. Someone (Linus?) proposed the solution of a 'magic page' which holds information like gettimeofday() stuff, but could be handled much more rapidly than a

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Mohammad A. Haque
It used to be.. flags : fpu vme de pse tsc msr pae but now called features It's a simple enough change. Contact me privately if you can't any avifile people to help. Jordan wrote: I have been running a plug in for xmms for some time that uses the aviplay program and

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Andi Kleen
On Fri, Nov 17, 2000 at 02:21:03PM +0100, Christoph Rohland wrote: Hi Jeff, On Fri, 17 Nov 2000, Jeff Garzik wrote: IIRC, this came up a long time ago WRT Apache, which made a lot of gettimeofday() calls. Someone (Linus?) proposed the solution of a 'magic page' which holds information

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Mikael Pettersson
Hmm, my CPUID vs /proc/cpuinfo comment seemed somewhat controversial. Tigran Aivazian wrote: Arguably, it is always better to parse /proc/cpuinfo instead of executing CPUID directly (think PCI -- drivers should _NOT_ get their irq/io/etc values from config space directly but only what the

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Jeff Garzik
Andi Kleen wrote: No it would not. Often you want cycle accurate couting for profiling purposes. Isn't that why /dev/cpu/%d/msr exists? -- Jeff Garzik | Building 1024 | The chief enemy of creativity is "good" sense MandrakeSoft| -- Picasso - To

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Andi Kleen
On Fri, Nov 17, 2000 at 08:40:27AM -0500, Jeff Garzik wrote: Andi Kleen wrote: No it would not. Often you want cycle accurate couting for profiling purposes. Isn't that why /dev/cpu/%d/msr exists? Requires either root privileges or is a big security hole. [of course rdtsc only works

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Arjan van de Ven
In article [EMAIL PROTECTED] you wrote: Andi Kleen wrote: No it would not. Often you want cycle accurate couting for profiling purposes. Isn't that why /dev/cpu/%d/msr exists? This is root only though.. (Yes, you can crash AMD boxes by reading MSR's) Greetings, Arjan van de Ven -

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Christoph Rohland
Hi Tigran, On Fri, 17 Nov 2000, Tigran Aivazian wrote: On Fri, 17 Nov 2000, Andi Kleen wrote: [of course rdtsc only works properly on UP or with bind_cpu()] I thought Linux kernel does synchronize them on boot? So, you are saying I cannot rely on this being 100% correct? Yes, it does so

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Alan Cox
I thought Linux kernel does synchronize them on boot? So, you are saying I cannot rely on this being 100% correct? Yes, it does so far. And if we cannot assume this to be correct in the microsecond scale on smp machines with homogenous non-powersaving cpus we will loose on some

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Andrea Arcangeli
On Fri, Nov 17, 2000 at 01:51:11PM +0100, Christoph Rohland wrote: gettimeofday is _way_ to slow for a lot of every day uses. So applications will use rdtsc until we have some really fast (non-syscall) way to have high resolution time diffs. During the x86-64 design I made sure that in x86-64

Re: Error in x86 CPU capabilities starting with test5/6

2000-11-17 Thread Christoph Rohland
Hi Andrea, On Fri, 17 Nov 2000, Andrea Arcangeli wrote: So as worse you'll have to wait x86-64 to get that lightweight vgettimeofday. Could I get this for i686? :-) Greetings Christoph - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a