On 5/2/06, Eric W. Biederman <[EMAIL PROTECTED]> wrote:
Vivek Goyal <[EMAIL PROTECTED]> writes: > On Mon, May 01, 2006 at 06:49:16PM +0900, Magnus Damm wrote: >> --- 0001/include/linux/kexec.h >> +++ work/include/linux/kexec.h 2006-05-01 11:13:14.000000000 +0900 >> @@ -69,6 +69,17 @@ struct kimage { >> unsigned long start; >> struct page *control_code_page; >> >> + /* page_table_a[] holds enough pages to create a new page table >> + * that maps the control page twice.. >> + */ >> + >> +#if defined(CONFIG_X86_32) && !defined(CONFIG_X86_PAE) >> + struct page *page_table_a[3]; /* (2 * pte) + pgd */ >> +#endif >> +#if defined(CONFIG_X86_32) && defined(CONFIG_X86_PAE) >> + struct page *page_table_a[5]; /* (2 * pte) + (2 * pmd) + pgd */ >> +#endif >> + > > Would it make a cleaner interface if these array of pointers are maintained > in arch dependent code as global variables instead of putting in arch > independent code. Existing code does something simlar. This becomes further > ugly when another array comes into the picture for x86_64 in next patch. > (page_table_b)Well global variables don't quite work in the normal case. However it probably makes most sense to maintain the needed variables in a structure on the control page. Which will keep them out of harms way, and won't require patches to the generic code.
I agree with both of you that the #ifdefs in struct kimage should be avoided, but I wonder if adding variables in a structure on the control page is the easiest and cleanest way. I think that defining a structure for each architecture in include/asm/kexec.h that is included in struct kimage is the best way to go. Then each architecture can have whatever data it wants there, and we both avoid #ifdefs in struct kimage _and_ we stay away from overly complicated code that just allocates, frees and parses architecture-dependent data. Thanks for the input, / magnus _______________________________________________ fastboot mailing list [email protected] https://lists.osdl.org/mailman/listinfo/fastboot
