Re: [Patch 5/8] ia64: implement crashkernel=auto

Andrew Morton
2009-08-22T00:24:07Z

On Fri, 21 Aug 2009 02:55:04 -0400
Amerigo Wang <amwang@redhat.com> wrote:

> +#ifdef CONFIG_KEXEC_AUTO_RESERVE
> +#define ARCH_HAS_DEFAULT_CRASH_SIZE
> +static inline
> +unsigned long long arch_default_crash_size(unsigned long long total_size)
> +{
> + if (total_size >= 4ULL<<30 && total_size < 12ULL<<30)
> + return 1ULL<<28;
> + else if (total_size >= 12ULL<<30 && total_size < 128ULL<<30)
> + return 1ULL<<29;
> + else if (total_size >= 128ULL<<30 && total_size < 256ULL<<30)
> + return 3ULL<<28;
> + else if (total_size >= 256ULL<<30 && total_size < 378ULL<<30)
> + return 1ULL<<30;
> + else if (total_size >= 318ULL<<30 && total_size < 512ULL<<30)
> + return 3ULL<<29;
> + else if (total_size >= 512ULL<<30 && total_size < 768ULL<<30)
> + return 2ULL<<30;
> + else if (total_size >= 768ULL<<30)
> + return 3ULL<<30;
> +}
> +#include <asm-generic/kexec.h>
> +#endif

a) Why on earth is this inlined?

b) Please consider making arch_default_crash_size() a __weak
function. You'll probably find the result to be pleasing.

c) If we can't use __weak then please don't add
ARCH_HAS_DEFAULT_CRASH_SIZE. Instead do this trick:

#ifndef arch_default_crash_size
static inline unsigned long long arch_default_crash_size(unsigned long long total_size)
{
...
}
#define arch_default_crash_size arch_default_crash_size
#endif

because i) it's good to standardise on something and ii) one less
symbol gets added to the kernel.

d) why is asm-generic/kexec.h only included in asm/kexec.h if
CONFIG_KEXEC_AUTO_RESERVE happened to be defined? That makes no
sense - there may be a multitude of reasons why asm/kexec.h wants
to include asm-generic/kexec.h.