Re: [PATCH v3] arch/sparc: support NR_CPUS = 4096

From	David Miller <davem@davemloft.net>
Newsgroups	linux.kernel
Subject	Re: [PATCH v3] arch/sparc: support NR_CPUS = 4096
Date	2017-06-06 22:50 +0200
Message-ID	<tPtAm-5iT-19@gated-at.bofh.it> (permalink)
References	<tPtqF-5fp-7@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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From: Jane Chu <jane.chu@oracle.com>
Date: Tue,  6 Jun 2017 14:32:29 -0600

> Linux SPARC64 limits NR_CPUS to 4064 because init_cpu_send_mondo_info()
> only allocates a single page for NR_CPUS mondo entries. Thus we cannot
> use all 4096 CPUs on some SPARC platforms.
> 
> To fix, allocate (2^order) pages where order is set according to the size
> of cpu_list for possible cpus. Since cpu_list_pa and cpu_mondo_block_pa
> are not used in asm code, there are no imm13 offsets from the base PA
> that will break because they can only reach one page.
> 
> Orabug: 25505750
> 
> Signed-off-by: Jane Chu <jane.chu@oracle.com>
> 
> Reviewed-by: Bob Picco <bob.picco@oracle.com>
> Reviewed-by: Atish Patra <atish.patra@oracle.com>

Looks a lot better, applied, thanks!

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[PATCH v3] arch/sparc: support NR_CPUS = 4096 Jane Chu <jane.chu@oracle.com> - 2017-06-06 22:40 +0200
  Re: [PATCH v3] arch/sparc: support NR_CPUS = 4096 David Miller <davem@davemloft.net> - 2017-06-06 22:50 +0200

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