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

Amerigo Wang
2009-08-24T01:59:29Z

Andrew Morton wrote:
> 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.
>

Good idea!

> 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.
>

Yes, agree. I will try b) which seems to be better than c).

> 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.
>
>
Hmm, yes? kernel/kexec.c includes linux/kexec.h which already includes
asm/kexec.h....