Re: [PATCH v2 3/9] arc: remove support for DISCONTIGMEM

Mike Rapoport
2021-06-04T14:49:41Z

On Fri, Jun 04, 2021 at 02:07:39PM +0000, Vineet Gupta wrote:
> On 6/3/21 11:49 PM, Mike Rapoport wrote:
> > From: Mike Rapoport <rppt@linux.ibm.com>
> >
> > DISCONTIGMEM was replaced by FLATMEM with freeing of the unused memory map
> > in v5.11.
> >
> > Remove the support for DISCONTIGMEM entirely.
> >
> > Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
>
> Looks non intrusive, but I'd still like to give this a spin on hardware
> - considering highmem on ARC has tendency to go sideways ;-)
> Can you please share a branch !

Sure:

https://git.kernel.org/pub/scm/linux/kernel/git/rppt/linux.git/log/?h=memory-models/rm-discontig/v2

> Acked-by: Vineet Gupta <vgupta@synopsys.com>

Thanks!

> Thx,
> -Vineet
>
> > ---
> > arch/arc/Kconfig | 13 ------------
> > arch/arc/include/asm/mmzone.h | 40 -----------------------------------
> > arch/arc/mm/init.c | 8 -------
> > 3 files changed, 61 deletions(-)
> > delete mode 100644 arch/arc/include/asm/mmzone.h
> >
> > diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
> > index 2d98501c0897..d8f51eb8963b 100644
> > --- a/arch/arc/Kconfig
> > +++ b/arch/arc/Kconfig
> > @@ -62,10 +62,6 @@ config SCHED_OMIT_FRAME_POINTER
> > config GENERIC_CSUM
> > def_bool y
> >
> > -config ARCH_DISCONTIGMEM_ENABLE
> > - def_bool n
> > - depends on BROKEN
> > -
> > config ARCH_FLATMEM_ENABLE
> > def_bool y
> >
> > @@ -344,15 +340,6 @@ config ARC_HUGEPAGE_16M
> >
> > endchoice
> >
> > -config NODES_SHIFT
> > - int "Maximum NUMA Nodes (as a power of 2)"
> > - default "0" if !DISCONTIGMEM
> > - default "1" if DISCONTIGMEM
> > - depends on NEED_MULTIPLE_NODES
> > - help
> > - Accessing memory beyond 1GB (with or w/o PAE) requires 2 memory
> > - zones.
> > -
> > config ARC_COMPACT_IRQ_LEVELS
> > depends on ISA_ARCOMPACT
> > bool "Setup Timer IRQ as high Priority"
> > diff --git a/arch/arc/include/asm/mmzone.h b/arch/arc/include/asm/mmzone.h
> > deleted file mode 100644
> > index b86b9d1e54dc..000000000000
> > --- a/arch/arc/include/asm/mmzone.h
> > +++ /dev/null
> > @@ -1,40 +0,0 @@
> > -/* SPDX-License-Identifier: GPL-2.0-only */
> > -/*
> > - * Copyright (C) 2016 Synopsys, Inc. (www.synopsys.com)
> > - */
> > -
> > -#ifndef _ASM_ARC_MMZONE_H
> > -#define _ASM_ARC_MMZONE_H
> > -
> > -#ifdef CONFIG_DISCONTIGMEM
> > -
> > -extern struct pglist_data node_data[];
> > -#define NODE_DATA(nid) (&node_data[nid])
> > -
> > -static inline int pfn_to_nid(unsigned long pfn)
> > -{
> > - int is_end_low = 1;
> > -
> > - if (IS_ENABLED(CONFIG_ARC_HAS_PAE40))
> > - is_end_low = pfn <= virt_to_pfn(0xFFFFFFFFUL);
> > -
> > - /*
> > - * node 0: lowmem: 0x8000_0000 to 0xFFFF_FFFF
> > - * node 1: HIGHMEM w/o PAE40: 0x0 to 0x7FFF_FFFF
> > - * HIGHMEM with PAE40: 0x1_0000_0000 to ...
> > - */
> > - if (pfn >= ARCH_PFN_OFFSET && is_end_low)
> > - return 0;
> > -
> > - return 1;
> > -}
> > -
> > -static inline int pfn_valid(unsigned long pfn)
> > -{
> > - int nid = pfn_to_nid(pfn);
> > -
> > - return (pfn <= node_end_pfn(nid));
> > -}
> > -#endif /* CONFIG_DISCONTIGMEM */
> > -
> > -#endif
> > diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
> > index 397a201adfe3..abfeef7bf6f8 100644
> > --- a/arch/arc/mm/init.c
> > +++ b/arch/arc/mm/init.c
> > @@ -32,11 +32,6 @@ unsigned long arch_pfn_offset;
> > EXPORT_SYMBOL(arch_pfn_offset);
> > #endif
> >
> > -#ifdef CONFIG_DISCONTIGMEM
> > -struct pglist_data node_data[MAX_NUMNODES] __read_mostly;
> > -EXPORT_SYMBOL(node_data);
> > -#endif
> > -
> > long __init arc_get_mem_sz(void)
> > {
> > return low_mem_sz;
> > @@ -147,9 +142,6 @@ void __init setup_arch_memory(void)
> > * to the hole is freed and ARC specific version of pfn_valid()
> > * handles the hole in the memory map.
> > */
> > -#ifdef CONFIG_DISCONTIGMEM
> > - node_set_online(1);
> > -#endif
> >
> > min_high_pfn = PFN_DOWN(high_mem_start);
> > max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz);
>

--
Sincerely yours,
Mike.