Messages in this thread | | | Date | Fri, 7 Jul 2023 13:56:14 +0200 | Subject | Re: [PATCH 2/2] mm: compaction: skip the memory hole rapidly when isolating free pages | From | David Hildenbrand <> |
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On 07.07.23 10:51, Baolin Wang wrote: > On my machine with below memory layout, and I can see it will take more > time to skip the larger memory hole (range: 0x100000000 - 0x1800000000) > when isolating free pages. So adding a new helper to skip the memory > hole rapidly, which can reduce the time consumed from about 70us to less > than 1us.
Can you clarify how this relates to the previous commit and mention that commit?
> > [ 0.000000] Zone ranges: > [ 0.000000] DMA [mem 0x0000000040000000-0x00000000ffffffff] > [ 0.000000] DMA32 empty > [ 0.000000] Normal [mem 0x0000000100000000-0x0000001fa7ffffff] > [ 0.000000] Movable zone start for each node > [ 0.000000] Early memory node ranges > [ 0.000000] node 0: [mem 0x0000000040000000-0x0000000fffffffff] > [ 0.000000] node 0: [mem 0x0000001800000000-0x0000001fa3c7ffff] > [ 0.000000] node 0: [mem 0x0000001fa3c80000-0x0000001fa3ffffff] > [ 0.000000] node 0: [mem 0x0000001fa4000000-0x0000001fa402ffff] > [ 0.000000] node 0: [mem 0x0000001fa4030000-0x0000001fa40effff] > [ 0.000000] node 0: [mem 0x0000001fa40f0000-0x0000001fa73cffff] > [ 0.000000] node 0: [mem 0x0000001fa73d0000-0x0000001fa745ffff] > [ 0.000000] node 0: [mem 0x0000001fa7460000-0x0000001fa746ffff] > [ 0.000000] node 0: [mem 0x0000001fa7470000-0x0000001fa758ffff] > [ 0.000000] node 0: [mem 0x0000001fa7590000-0x0000001fa7ffffff] > > Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> > --- > mm/compaction.c | 30 +++++++++++++++++++++++++++++- > 1 file changed, 29 insertions(+), 1 deletion(-) > > diff --git a/mm/compaction.c b/mm/compaction.c > index 43358efdbdc2..9641e2131901 100644 > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -249,11 +249,31 @@ static unsigned long skip_offline_sections(unsigned long start_pfn) > > return 0; > } > + > +static unsigned long skip_offline_sections_reverse(unsigned long start_pfn) > +{ > + unsigned long start_nr = pfn_to_section_nr(start_pfn); > + > + if (!start_nr || online_section_nr(start_nr)) > + return 0; > + > + while (start_nr-- > 0) { > + if (online_section_nr(start_nr)) > + return section_nr_to_pfn(start_nr) + PAGES_PER_SECTION - 1; > + } > + > + return 0; > +} > #else > static unsigned long skip_offline_sections(unsigned long start_pfn) > { > return 0; > } > + > +static unsigned long skip_offline_sections_reverse(unsigned long start_pfn) > +{ > + return 0; > +} > #endif > > /* > @@ -1668,8 +1688,16 @@ static void isolate_freepages(struct compact_control *cc) > > page = pageblock_pfn_to_page(block_start_pfn, block_end_pfn, > zone); > - if (!page) > + if (!page) { > + unsigned long next_pfn; > + > + next_pfn = skip_offline_sections_reverse(block_start_pfn); > + if (next_pfn) > + block_start_pfn = max(pageblock_start_pfn(next_pfn), > + low_pfn); > + > continue; > + } > > /* Check the block is suitable for migration */ > if (!suitable_migration_target(cc, page))
LGTM
Acked-by: David Hildenbrand <david@redhat.com>
-- Cheers,
David / dhildenb
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