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Sender: Ingo Molnar <mingo.kernel.org@gmail.com>
Date: Sun, 24 Mar 2024 11:27:44 +0100
From: Ingo Molnar <mingo@kernel.org>
To: Baoquan He <bhe@redhat.com>
Cc: kexec@lists.infradead.org, linux-kernel@vger.kernel.org, x86@kernel.org,
	akpm@linux-foundation.org, chenhuacai@loongson.cn,
	dyoung@redhat.com, jbohac@suse.cz, lihuafei1@huawei.com,
	chenhaixiang3@huawei.com
Subject: Re: [PATCH] crash: use macro to add crashk_res into iomem early for
 specific arch
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* Baoquan He <bhe@redhat.com> wrote:

> On 03/24/24 at 05:06am, Ingo Molnar wrote:
> > 
> > * Baoquan He <bhe@redhat.com> wrote:
> > 
> ......snip
> > > ---
> > >  arch/x86/include/asm/crash_reserve.h | 2 ++
> > >  kernel/crash_reserve.c               | 7 +++++++
> > >  2 files changed, 9 insertions(+)
> > > 
> > > diff --git a/arch/x86/include/asm/crash_reserve.h b/arch/x86/include/asm/crash_reserve.h
> > > index 152239f95541..4681a543eba3 100644
> > > --- a/arch/x86/include/asm/crash_reserve.h
> > > +++ b/arch/x86/include/asm/crash_reserve.h
> > > @@ -39,4 +39,6 @@ static inline unsigned long crash_low_size_default(void)
> > >  #endif
> > >  }
> > >  
> > > +# define HAVE_ARCH_ADD_CRASH_RES_TO_IOMEM_EARLY
> > > +
> > 
> > Any reason for that stray space?
> 
> No clear reason. I saw stray space was added for macro definning when my
> below patch was merged, not sure if this is preferred.

No, it's not preferred - and I don't see any stray spaces added in the 
code added by:

> commit 85fcde402db1 ("kexec: split crashkernel reservation code out from crash_core.c")

Anyway, please just remove it.

> And there are a lot of "# define " when searching with 'git grep "# 
> define " arch/x86/include/'.

The overwhelming majority of those are not standalone defines like 
yours, but nested/conditional defines where the space is justified:

#ifdef CONFIG_X86_32
# define MAX_IO_APICS 64
# define MAX_LOCAL_APIC 256
#else
# define MAX_IO_APICS 128
# define MAX_LOCAL_APIC 32768
#endif

Thanks,

	Ingo