swapspace in HHL 2.0

swapspace in HHL 2.0

[James F Dougherty]

Hi,

I used initdconfig to enable mountall.sh and have an /etc/fstab like
so:

# /etc/fstab: static file system information.
#
# <file system> <mount point>   <type>  <options>               <dump>  <pass>
/dev/root       /               auto    defaults,errors=remount-ro      0 0
/proc           /proc           proc    defaults                        0 0
/dev/hda1       /               auto    rw                              0 1
/dev/hda2       swap            swap    defaults                        0 2

When the system boots, it says that it is enabling the swapspace, however
if you cat /proc/meminfo, it shows that it is really not enabled.
Now, if you do a "swapon -a" instead of "swapon -a 2" (like in the mountall.sh)
then swap comes on.

What am I doing wrong?

MTIA				-James

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Re: swapspace in HHL 2.0

[Mark Hatle]

James F Dougherty wrote:
>
> Hi,
>
> I used initdconfig to enable mountall.sh and have an /etc/fstab like
> so:
>
> # /etc/fstab: static file system information.
> #
> # <file system> <mount point>   <type>  <options>               <dump>  <pass>
> /dev/root       /               auto    defaults,errors=remount-ro      0 0
> /proc           /proc           proc    defaults                        0 0
> /dev/hda1       /               auto    rw                              0 1
> /dev/hda2       swap            swap    defaults                        0 2
>
> When the system boots, it says that it is enabling the swapspace, however
> if you cat /proc/meminfo, it shows that it is really not enabled.
> Now, if you do a "swapon -a" instead of "swapon -a 2" (like in the mountall.sh)
> then swap comes on.
>
> What am I doing wrong?

The file on one of my targets is:

/dev/hda3       /               ext2    defaults,errors=remount-ro
1 1
/dev/hda4       /usr/local      ext2    defaults,errors=remount-ro
1 2
/dev/hda2       /boot           hfs     defaults
1 2
proc            /proc           proc    defaults
0 0
/var/swap       swap            swap    defaults
0 0

(and that works)  FYI my swap is in a file not a partition, that way I
can increase/decrease the size of the swap file at will...  (Only down
side, is that swap is not read/write until after the root filesystem is
mounted in my case...)

So the only thing I can think of the is "pass" flag you have set to 2.
I don't know why that would effect anything though.

Look at the "checkroot.sh" and "mountall.sh" initscripts, they enable
the swap spaces.

--Mark

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applications in HHL 2.0, 405GP

[David Updegraff]

Hi.

I need Tcl/Expect in our environment and HHL20 does not appear to include it,
and bringing it over from other PPC distributions (eg. Debian) just traps out
with "Illegal Instruction" ... which I presume is some floating point
instruction which the 405GP lacks.

My approach is to go get the Tcl/Expect sources and start building away..

Is there a better approach?  Is there a repository anywere where
PPC -msoft-float RPMs live that I could borrow from/contribute to?

Anyway, I thought it was the "theory" that the kernel was trapping the
float instructions and emulating them...???

Please advise. Thanx.

--
Dave Updegraff / dave@cray.com / 218-525-1154


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Re: applications in HHL 2.0, 405GP

[Joe Green]

David Updegraff wrote:
> Anyway, I thought it was the "theory" that the kernel was trapping the
> float instructions and emulating them...???

Remember that it's not just a matter of configuring math emulation into
the kernel.  The function call ABI is different for soft vs. hard
float, so library calls will go kerflooey if you mix the two.  If you
stick to all hard float user space, you can use kernel math emulation.

--
Joe Green <jgreen@mvista.com>
MontaVista Software, Inc.

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Re: applications in HHL 2.0, 405GP

[David Gibson]

On Tue, Sep 18, 2001 at 12:05:09PM -0700, Joe Green wrote:
>
> David Updegraff wrote:
> > Anyway, I thought it was the "theory" that the kernel was trapping the
> > float instructions and emulating them...???
>
> Remember that it's not just a matter of configuring math emulation into
> the kernel.  The function call ABI is different for soft vs. hard
> float, so library calls will go kerflooey if you mix the two.  If you
> stick to all hard float user space, you can use kernel math emulation.

Except of course that the 4xx port as it stands doesn't support kernel
math emulation.  The patch below adds support (and also lets 4xx do
the other emulated instructions that most of the ppc ports support).
Anyone care to merge it?

diff -urN /home/dgibson/kernel/linuxppc_2_4_devel/arch/ppc/kernel/traps.c linux-bungo/arch/ppc/kernel/traps.c
--- /home/dgibson/kernel/linuxppc_2_4_devel/arch/ppc/kernel/traps.c	Tue Sep  4 19:13:42 2001
+++ linux-bungo/arch/ppc/kernel/traps.c	Wed Sep 12 13:16:43 2001
@@ -267,6 +267,7 @@
 {
 #if defined(CONFIG_4xx)
 	unsigned int esr = mfspr(SPRN_ESR);
+	extern int do_mathemu(struct pt_regs *regs);

 	if (esr & ESR_PTR) {
 #if defined(CONFIG_XMON) || defined(CONFIG_KGDB)
@@ -275,9 +276,19 @@
 #endif
 		_exception(SIGTRAP, regs);
 	} else {
-		_exception(SIGILL, regs);
+		int errcode;
+#ifdef CONFIG_MATH_EMULATION
+		if (do_mathemu(regs) == 0)
+			return;
+#endif /* CONFIG_MATH_EMULATION */
+		if ((errcode = emulate_instruction(regs))) {
+			if (errcode == -EFAULT)
+				_exception(SIGBUS, regs);
+			else
+				_exception(SIGILL, regs);
+		}
 	}
-#else
+#else /* ! CONFIG_4xx */
 	if (regs->msr & 0x100000) {
 		/* IEEE FP exception */
 		_exception(SIGFPE, regs);
@@ -286,7 +297,7 @@
 #if defined(CONFIG_XMON) || defined(CONFIG_KGDB)
 		if (debugger_bpt(regs))
 			return;
-#endif
+#endif /* defined(CONFIG_XMON) || defined(CONFIG_KGDB) */
 		_exception(SIGTRAP, regs);
 	} else {
 		/* Try to emulate it if we should. */


--
David Gibson			| For every complex problem there is a
david@gibson.dropbear.id.au	| solution which is simple, neat and
				| wrong.  -- H.L. Mencken
http://www.ozlabs.org/people/dgibson


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