> On Apr 12, 2020, at 3:48 PM, Mike Rapoport <rppt****@kerne*****> wrote: > > From: Baoquan He <bhe****@redha*****> > > When called during boot the memmap_init_zone() function checks if each PFN > is valid and actually belongs to the node being initialized using > early_pfn_valid() and early_pfn_in_nid(). > > Each such check may cost up to O(log(n)) where n is the number of memory > banks, so for large amount of memory overall time spent in early_pfn*() > becomes substantial. > > Since the information is anyway present in memblock, we can iterate over > memblock memory regions in memmap_init() and only call memmap_init_zone() > for PFN ranges that are know to be valid and in the appropriate node. > > Signed-off-by: Baoquan He <bhe****@redha*****> > Signed-off-by: Mike Rapoport <rppt****@linux*****> > --- > mm/page_alloc.c | 26 ++++++++++++++++---------- > 1 file changed, 16 insertions(+), 10 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 7f6a3081edb8..c43ce8709457 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -5995,14 +5995,6 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, > * function. They do not exist on hotplugged memory. > */ > if (context == MEMMAP_EARLY) { > - if (!early_pfn_valid(pfn)) { > - pfn = next_pfn(pfn); > - continue; > - } > - if (!early_pfn_in_nid(pfn, nid)) { > - pfn++; > - continue; > - } This causes a compilation warning from Clang, mm/page_alloc.c:5917:39: warning: unused function 'next_pfn' [-Wunused-function] static inline __meminit unsigned long next_pfn(unsigned long pfn) This should fix it, diff --git a/mm/page_alloc.c b/mm/page_alloc.c index d469384c9ca7..b48336e20bdc 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5912,23 +5912,6 @@ overlap_memmap_init(unsigned long zone, unsigned long *pfn) return false; } -#ifdef CONFIG_SPARSEMEM -/* Skip PFNs that belong to non-present sections */ -static inline __meminit unsigned long next_pfn(unsigned long pfn) -{ - const unsigned long section_nr = pfn_to_section_nr(++pfn); - - if (present_section_nr(section_nr)) - return pfn; - return section_nr_to_pfn(next_present_section_nr(section_nr)); -} -#else -static inline __meminit unsigned long next_pfn(unsigned long pfn) -{ - return pfn++; -} -#endif - /* * Initially all pages are reserved - free ones are freed * up by memblock_free_all() once the early boot process is > if (overlap_memmap_init(zone, &pfn)) > continue; > if (defer_init(nid, pfn, end_pfn)) > @@ -6118,9 +6110,23 @@ static void __meminit zone_init_free_lists(struct zone *zone) > } > > void __meminit __weak memmap_init(unsigned long size, int nid, > - unsigned long zone, unsigned long start_pfn) > + unsigned long zone, > + unsigned long range_start_pfn) > { > - memmap_init_zone(size, nid, zone, start_pfn, MEMMAP_EARLY, NULL); > + unsigned long start_pfn, end_pfn; > + unsigned long range_end_pfn = range_start_pfn + size; > + int i; > + > + for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) { > + start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn); > + end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn); > + > + if (end_pfn > start_pfn) { > + size = end_pfn - start_pfn; > + memmap_init_zone(size, nid, zone, start_pfn, > + MEMMAP_EARLY, NULL); > + } > + } > } > > static int zone_batchsize(struct zone *zone) > -- > 2.25.1 > >
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