Messages in this thread | | | Date | Fri, 06 Mar 2009 14:06:31 -0800 | From | Jeremy Fitzhardinge <> | Subject | Re: [PATCH] x86: introduce bootmem_state -v2 |
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Ingo Molnar wrote: > * Andrew Morton <akpm@linux-foundation.org> wrote: > > >> On Fri, 6 Mar 2009 20:12:49 +0100 >> Ingo Molnar <mingo@elte.hu> wrote: >> >> >>> * Yinghai Lu <yinghai@kernel.org> wrote: >>> >>> >>>> Impact: cleanup >>>> >>>> extend after_bootmem and after_init_bootmem to bootmem_state >>>> and will have BEFORE_BOOTMEM, DURING_BOOTMEM, AFTER_BOOTMEM >>>> >>>> v2: style changes according to ingo >>>> >>>> Signed-off-by: Yinghai Lu <yinghai@kernel.org> >>>> >>>> --- >>>> arch/x86/kernel/setup.c | 1 + >>>> arch/x86/mm/init.c | 13 +++++++------ >>>> arch/x86/mm/init_32.c | 28 ++++++++++++++++++++-------- >>>> arch/x86/mm/init_64.c | 33 +++++++++++++++++++-------------- >>>> include/linux/mm.h | 9 +++++++++ >>>> 5 files changed, 56 insertions(+), 28 deletions(-) >>>> >>>> Index: linux-2.6/include/linux/mm.h >>>> =================================================================== >>>> --- linux-2.6.orig/include/linux/mm.h >>>> +++ linux-2.6/include/linux/mm.h >>>> @@ -1067,6 +1067,15 @@ extern void __init mmap_init(void); >>>> extern void show_mem(void); >>>> extern void si_meminfo(struct sysinfo * val); >>>> extern void si_meminfo_node(struct sysinfo *val, int nid); >>>> + >>>> +enum bootmem_state { >>>> + BEFORE_BOOTMEM, >>>> + DURING_BOOTMEM, >>>> + AFTER_BOOTMEM >>>> +}; >>>> + >>>> +extern enum bootmem_state bootmem_state; >>>> + >>>> extern int after_bootmem; >>>> >>> Btw., the after_bootmem variable itself should either move to >>> x86 (and arch/sh), or should be defined in mm/bootmem.c. >>> >>> Right now we have this weird mm.h construct that is not actually >>> useful to generic code. >>> >>> Andrew, what would be your preference? >>> >>> >> If two architectures are using it then it should be provided >> by core kernel? >> >> This is obvious if the state transitions are occurring in >> core-kernel code, but if the transitions are happening in arch >> code then making it a core concept assumes consistency between >> different architectures which might not exist. >> >> IOW: dunno. >> > > Core kernel could provide a wrapper allocator which calls the > right method depending on which state we are in. It will call > bootmem_alloc() if called early, and kmalloc() if called later. > Or something like that. Would there be any utility in that? >
Yes, so long as you're never intending to free the memory (since you won't know which free function to use for a given pointer - assuming one even exists). And code which does:
p = use_anytime_alloctor();
... kfree(p); /* I know it was really allocated by kmalloc */
should be shot.
J
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