Re: Slow Kernel Boot

["Daniel P. Berrange" <berrange-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

On Tue, Jan 08, 2008 at 11:13:08AM -0800, Dave Hansen wrote:
> On Tue, 2008-01-08 at 12:12 +0530, Amit Shah wrote:
> > > BIOS-provided physical RAM map:
> > >  BIOS-e820: 0000000000000000 - 000000000009fc00 (usable)
> > >  BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)
> > >  BIOS-e820: 00000000000e8000 - 0000000000100000 (reserved)
> > >  BIOS-e820: 0000000000100000 - 00000000fffbd000 (usable)
> > >  BIOS-e820: 00000000fffbd000 - 00000000ffff0000 (reserved)
> > >
> > > Note that this is with '-m 1G'!!  It looks to me like one of those
> > 
> > And there lies the problem. qemu doesn't understand suffixes like 'G'.
> > If you 
> > pass -m 1024, you'll boot just fine.
> > 
> > This is really annoying of qemu (it should either accept that input
> > properly 
> > or bail out); a patch is welcome!
> 
> OK.  Here's a function stolen blatantly from the kernel.  Seems to work

What license was this under originally ? The kernel is typically GPLv2,
while QEMU's core infrastructure is BSD (only some device emulation
is GPL). So not a good idea if you want this to go into upstream QEMU.

> --- orig/qemu-0.9.1/vl.c	2008-01-06 11:38:42.000000000 -0800
> +++ qemu-0.9.1/vl.c	2008-01-08 11:23:29.000000000 -0800
> @@ -8052,6 +8052,47 @@
>  }
>  #endif
>  
> +/**
> + *	memparse - parse a string with mem suffixes into a number of bytes
> + *	@ptr: Where parse begins
> + *
> + *	Parses a string into a number.  The number stored at @ptr is
> + *	potentially suffixed with %M (for megabytes, or 1048576 bytes)
> + *	or %G (for gigabytes, or 1073741824).  If the number is
> + *	suffixed with M or G, then the return value is the number
> + *	multiplied by one megabyte or one gigabyte, respectively. No
> + *	suffix implies megabytes.
> + */
> +
> +unsigned long long memparse (const char *ptr)
> +{
> +	char *endptr;
> +	unsigned long ret = strtoull(ptr, &endptr, 0);

32-bit overflow here on i686. Should be  unsigned long long if 
you want to support > 2 G on a 32-bit platform.

Dan.
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