Commit 9d1d887d authored May 13, 2019 by David Hildenbrand Committed by Linus Torvalds May 14, 2019

mm/memory_hotplug: make __remove_section() never fail

Let's just warn in case a section is not valid instead of failing to
remove somewhere in the middle of the process, returning an error that
will be mostly ignored by callers.

Link: http://lkml.kernel.org/r/20190409100148.24703-4-david@redhat.com


Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: Andrew Banman <andrew.banman@hpe.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Mike Travis <mike.travis@hpe.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent cb7b3a36

mm/memory_hotplug.c

+9 −13

Original line number	Diff line number	Diff line
		@@ -516,15 +516,15 @@ static void __remove_zone(struct zone *zone, unsigned long start_pfn)
		pgdat_resize_unlock(zone->zone_pgdat, &flags);
		}

		static int __remove_section(struct zone zone, struct mem_section ms,
		unsigned long map_offset, struct vmem_altmap *altmap)
		static void __remove_section(struct zone zone, struct mem_section ms,
		unsigned long map_offset,
		struct vmem_altmap *altmap)
		{
		unsigned long start_pfn;
		int scn_nr;
		int ret = -EINVAL;

		if (!valid_section(ms))
		return ret;
		if (WARN_ON_ONCE(!valid_section(ms)))
		return;

		unregister_memory_section(ms);

		@@ -533,7 +533,6 @@ static int __remove_section(struct zone zone, struct mem_section ms,
		__remove_zone(zone, start_pfn);

		sparse_remove_one_section(zone, ms, map_offset, altmap);
		return 0;
		}

		/**
		@@ -553,7 +552,7 @@ int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
		{
		unsigned long i;
		unsigned long map_offset = 0;
		int sections_to_remove, ret = 0;
		int sections_to_remove;

		/* In the ZONE_DEVICE case device driver owns the memory region */
		if (is_dev_zone(zone)) {
		@@ -574,16 +573,13 @@ int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
		unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION;

		cond_resched();
		ret = __remove_section(zone, __pfn_to_section(pfn), map_offset,
		__remove_section(zone, __pfn_to_section(pfn), map_offset,
		altmap);
		map_offset = 0;
		if (ret)
		break;
		}

		set_zone_contiguous(zone);

		return ret;
		return 0;
		}
		#endif /* CONFIG_MEMORY_HOTREMOVE */

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