Hi Akashi, On 09/07/18 06:49, AKASHI Takahiro wrote: > On Tue, Jul 03, 2018 at 05:36:24PM +0100, James Morse wrote: >> On 23/06/18 03:20, AKASHI Takahiro wrote: >>> Memblock list is another source for usable system memory layout. >>> A merged new arch_kexec_walk_mem() will walk through either io resource >>> list or memblock list depending on CONFIG_ARCH_DISCARD_MEMBLOCK so that >>> arm64, in addition to powerpc, will be able to utilize this generic >>> function for kexec_file. >> >>> diff --git a/arch/powerpc/kernel/machine_kexec_file_64.c b/arch/powerpc/kernel/machine_kexec_file_64.c >>> index 0bd23dc789a4..3d4be91786ce 100644 >>> --- a/arch/powerpc/kernel/machine_kexec_file_64.c >>> +++ b/arch/powerpc/kernel/machine_kexec_file_64.c >>> diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c >>> index 63c7ce1c0c3e..563acd1c9a61 100644 >>> --- a/kernel/kexec_file.c >>> +++ b/kernel/kexec_file.c >>> @@ -16,6 +16,7 @@ >>> #include <linux/file.h> >>> #include <linux/slab.h> >>> #include <linux/kexec.h> >>> +#include <linux/memblock.h> >>> #include <linux/mutex.h> >>> #include <linux/list.h> >>> #include <linux/fs.h> >>> @@ -501,6 +502,53 @@ static int locate_mem_hole_callback(struct resource *res, void *arg) >>> return locate_mem_hole_bottom_up(start, end, kbuf); >>> } >>> >>> +#if defined(CONFIG_HAVE_MEMBLOCK) && !defined(CONFIG_ARCH_DISCARD_MEMBLOCK) >> >> The only caller is also guarded by these same ifdefs. Can't we remove this and >> rely on the compilers dead-code elimination to remove this function when its not >> needed? > > I don't think we can remove this #ifdef. > "for_each_free_mem_range[_reverse]()" is defined under CONFIG_HAVE_MEMBLOCK > in memblock.h. If some architecture wants to support KEXEC_FILE but > doesn't have HAVE_MEMBLOCK, compiling kexec_file.c will fail. Ah, I'd missed this, turns out memblock isn't ubiquitous! Thanks, James _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
