Linux-MIPS Archive on lore.kernel.org
 help / color / Atom feed
From: Daniel Axtens <dja@axtens.net>
To: Mike Rapoport <rppt@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>, Baoquan He <bhe@redhat.com>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Borislav Petkov <bp@alien8.de>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Christoph Hellwig <hch@lst.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Emil Renner Berthing <kernel@esmil.dk>,
	Ingo Molnar <mingo@redhat.com>,
	Hari Bathini <hbathini@linux.ibm.com>,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	Max Filippov <jcmvbkbc@gmail.com>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Michal Simek <monstr@monstr.eu>,
	Mike Rapoport <rppt@linux.ibm.com>,
	Mike Rapoport <rppt@kernel.org>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Paul Mackerras <paulus@samba.org>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Russell King <linux@armlinux.org.uk>,
	Stafford Horne <shorne@gmail.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Will Deacon <will@kernel.org>,
	Yoshinori Sato <ysato@users.sourceforge.jp>,
	clang-built-linux@googlegroups.com,
	iommu@lists.linux-foundation.org, linux-arch@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-c6x-dev@linux-c6x.org, linux-kernel@vger.kernel.org,
	linux-mips@vger.kernel.org, linux-mm@kvack.org,
	linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org,
	linux-sh@vger.kernel.org, linux-xtensa@linux-xtensa.org,
	linuxppc-dev@lists.ozlabs.org, openrisc@lists.librecores.org,
	sparclinux@vger.kernel.org,
	uclinux-h8-devel@lists.sourceforge.jp, x86@kernel.org
Subject: Re: [PATCH v2 01/17] KVM: PPC: Book3S HV: simplify kvm_cma_reserve()
Date: Tue, 04 Aug 2020 23:53:15 +1000
Message-ID: <87tuxio6us.fsf@dja-thinkpad.axtens.net> (raw)
In-Reply-To: <20200802163601.8189-2-rppt@kernel.org>

Hi Mike,

>
> The memory size calculation in kvm_cma_reserve() traverses memblock.memory
> rather than simply call memblock_phys_mem_size(). The comment in that
> function suggests that at some point there should have been call to
> memblock_analyze() before memblock_phys_mem_size() could be used.
> As of now, there is no memblock_analyze() at all and
> memblock_phys_mem_size() can be used as soon as cold-plug memory is
> registerd with memblock.
>
> Replace loop over memblock.memory with a call to memblock_phys_mem_size().
>
> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
> ---
>  arch/powerpc/kvm/book3s_hv_builtin.c | 11 ++---------
>  1 file changed, 2 insertions(+), 9 deletions(-)
>
> diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c
> index 7cd3cf3d366b..56ab0d28de2a 100644
> --- a/arch/powerpc/kvm/book3s_hv_builtin.c
> +++ b/arch/powerpc/kvm/book3s_hv_builtin.c
> @@ -95,22 +95,15 @@ EXPORT_SYMBOL_GPL(kvm_free_hpt_cma);
>  void __init kvm_cma_reserve(void)
>  {
>  	unsigned long align_size;
> -	struct memblock_region *reg;
> -	phys_addr_t selected_size = 0;
> +	phys_addr_t selected_size;
>  
>  	/*
>  	 * We need CMA reservation only when we are in HV mode
>  	 */
>  	if (!cpu_has_feature(CPU_FTR_HVMODE))
>  		return;
> -	/*
> -	 * We cannot use memblock_phys_mem_size() here, because
> -	 * memblock_analyze() has not been called yet.
> -	 */
> -	for_each_memblock(memory, reg)
> -		selected_size += memblock_region_memory_end_pfn(reg) -
> -				 memblock_region_memory_base_pfn(reg);
>  
> +	selected_size = PHYS_PFN(memblock_phys_mem_size());
>  	selected_size = (selected_size * kvm_cma_resv_ratio / 100) << PAGE_SHIFT;

I think this is correct, but PHYS_PFN does x >> PAGE_SHIFT and then the
next line does x << PAGE_SHIFT, so I think we could combine those two
lines as:

selected_size = PAGE_ALIGN(memblock_phys_mem_size() * kvm_cma_resv_ratio / 100);

(I think that might technically change it from aligning down to aligning
up but I don't think 1 page matters here.)

Kind regards,
Daniel


>  	if (selected_size) {
>  		pr_debug("%s: reserving %ld MiB for global area\n", __func__,
> -- 
> 2.26.2

  reply index

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-02 16:35 [PATCH v2 00/17] memblock: seasonal cleaning^w cleanup Mike Rapoport
2020-08-02 16:35 ` [PATCH v2 01/17] KVM: PPC: Book3S HV: simplify kvm_cma_reserve() Mike Rapoport
2020-08-04 13:53   ` Daniel Axtens [this message]
2020-08-02 16:35 ` [PATCH v2 02/17] dma-contiguous: simplify cma_early_percent_memory() Mike Rapoport
2020-08-05  3:50   ` Baoquan He
2020-08-02 16:35 ` [PATCH v2 03/17] arm, xtensa: simplify initialization of high memory pages Mike Rapoport
2020-08-02 16:35 ` [PATCH v2 04/17] arm64: numa: simplify dummy_numa_init() Mike Rapoport
2020-08-02 16:35 ` [PATCH v2 05/17] h8300, nds32, openrisc: simplify detection of memory extents Mike Rapoport
2020-08-02 16:35 ` [PATCH v2 06/17] riscv: drop unneeded node initialization Mike Rapoport
2020-08-02 16:35 ` [PATCH v2 07/17] mircoblaze: drop unneeded NUMA and sparsemem initializations Mike Rapoport
2020-08-02 16:35 ` [PATCH v2 08/17] memblock: make for_each_memblock_type() iterator private Mike Rapoport
2020-08-02 16:35 ` [PATCH v2 09/17] memblock: make memblock_debug and related functionality private Mike Rapoport
2020-08-02 16:35 ` [PATCH v2 10/17] memblock: reduce number of parameters in for_each_mem_range() Mike Rapoport
2020-08-02 16:35 ` [PATCH v2 11/17] arch, mm: replace for_each_memblock() with for_each_mem_pfn_range() Mike Rapoport
2020-08-05  3:57   ` Baoquan He
2020-08-02 16:35 ` [PATCH v2 12/17] arch, drivers: replace for_each_membock() with for_each_mem_range() Mike Rapoport
2020-08-05 11:00   ` Thomas Bogendoerfer
2020-08-02 16:35 ` [PATCH v2 13/17] x86/setup: simplify initrd relocation and reservation Mike Rapoport
2020-08-02 18:01   ` Ingo Molnar
2020-08-05  4:20   ` Baoquan He
2020-08-05  5:59     ` Mike Rapoport
2020-08-02 16:35 ` [PATCH v2 14/17] x86/setup: simplify reserve_crashkernel() Mike Rapoport
2020-08-02 18:02   ` Ingo Molnar
2020-08-05  6:00   ` Baoquan He
2020-08-02 16:35 ` [PATCH v2 15/17] memblock: remove unused memblock_mem_size() Mike Rapoport
2020-08-05  8:29   ` Baoquan He
2020-08-02 16:36 ` [PATCH v2 16/17] memblock: implement for_each_reserved_mem_region() using __next_mem_region() Mike Rapoport
2020-08-05  9:11   ` Baoquan He
2020-08-05 17:11   ` Miguel Ojeda
2020-08-02 16:36 ` [PATCH v2 17/17] memblock: use separate iterators for memory and reserved regions Mike Rapoport
2020-08-02 18:03   ` Ingo Molnar
2020-08-05  9:29   ` Baoquan He
2020-08-05 10:58   ` Thomas Bogendoerfer
2020-08-05 17:10   ` Miguel Ojeda

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=87tuxio6us.fsf@dja-thinkpad.axtens.net \
    --to=dja@axtens.net \
    --cc=akpm@linux-foundation.org \
    --cc=benh@kernel.crashing.org \
    --cc=bhe@redhat.com \
    --cc=bp@alien8.de \
    --cc=catalin.marinas@arm.com \
    --cc=clang-built-linux@googlegroups.com \
    --cc=dave.hansen@linux.intel.com \
    --cc=hbathini@linux.ibm.com \
    --cc=hch@lst.de \
    --cc=iommu@lists.linux-foundation.org \
    --cc=jcmvbkbc@gmail.com \
    --cc=kernel@esmil.dk \
    --cc=linux-arch@vger.kernel.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-c6x-dev@linux-c6x.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mips@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=linux-riscv@lists.infradead.org \
    --cc=linux-s390@vger.kernel.org \
    --cc=linux-sh@vger.kernel.org \
    --cc=linux-xtensa@linux-xtensa.org \
    --cc=linux@armlinux.org.uk \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=luto@kernel.org \
    --cc=m.szyprowski@samsung.com \
    --cc=mingo@redhat.com \
    --cc=monstr@monstr.eu \
    --cc=mpe@ellerman.id.au \
    --cc=openrisc@lists.librecores.org \
    --cc=palmer@dabbelt.com \
    --cc=paul.walmsley@sifive.com \
    --cc=paulus@samba.org \
    --cc=peterz@infradead.org \
    --cc=rppt@kernel.org \
    --cc=rppt@linux.ibm.com \
    --cc=shorne@gmail.com \
    --cc=sparclinux@vger.kernel.org \
    --cc=tglx@linutronix.de \
    --cc=uclinux-h8-devel@lists.sourceforge.jp \
    --cc=will@kernel.org \
    --cc=x86@kernel.org \
    --cc=ysato@users.sourceforge.jp \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-MIPS Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-mips/0 linux-mips/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-mips linux-mips/ https://lore.kernel.org/linux-mips \
		linux-mips@vger.kernel.org
	public-inbox-index linux-mips

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-mips


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git