| Message ID | 155977188458.2443951.9573565800736334460.stgit@dwillia2-desk3.amr.corp.intel.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | mm: Sub-section memory hotplug support | expand |
On Wed, Jun 05, 2019 at 02:58:04PM -0700, Dan Williams wrote: >Sub-section hotplug support reduces the unit of operation of hotplug >from section-sized-units (PAGES_PER_SECTION) to sub-section-sized units >(PAGES_PER_SUBSECTION). Teach shrink_{zone,pgdat}_span() to consider >PAGES_PER_SUBSECTION boundaries as the points where pfn_valid(), not >valid_section(), can toggle. > >Cc: Michal Hocko <mhocko@suse.com> >Cc: Vlastimil Babka <vbabka@suse.cz> >Cc: Logan Gunthorpe <logang@deltatee.com> >Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> >Reviewed-by: Oscar Salvador <osalvador@suse.de> >Signed-off-by: Dan Williams <dan.j.williams@intel.com> >--- > mm/memory_hotplug.c | 29 ++++++++--------------------- > 1 file changed, 8 insertions(+), 21 deletions(-) > >diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c >index 7b963c2d3a0d..647859a1d119 100644 >--- a/mm/memory_hotplug.c >+++ b/mm/memory_hotplug.c >@@ -318,12 +318,8 @@ static unsigned long find_smallest_section_pfn(int nid, struct zone *zone, > unsigned long start_pfn, > unsigned long end_pfn) > { >- struct mem_section *ms; >- >- for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SECTION) { >- ms = __pfn_to_section(start_pfn); >- >- if (unlikely(!valid_section(ms))) >+ for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SUBSECTION) { >+ if (unlikely(!pfn_valid(start_pfn))) > continue; Hmm, we change the granularity of valid section from SECTION to SUBSECTION. But we didn't change the granularity of node id and zone information. For example, we found the node id of a pfn mismatch, we can skip the whole section instead of a subsection. Maybe this is not a big deal. > > if (unlikely(pfn_to_nid(start_pfn) != nid)) >@@ -343,15 +339,12 @@ static unsigned long find_biggest_section_pfn(int nid, struct zone *zone, > unsigned long start_pfn, > unsigned long end_pfn) > { >- struct mem_section *ms; > unsigned long pfn; > > /* pfn is the end pfn of a memory section. */ > pfn = end_pfn - 1; >- for (; pfn >= start_pfn; pfn -= PAGES_PER_SECTION) { >- ms = __pfn_to_section(pfn); >- >- if (unlikely(!valid_section(ms))) >+ for (; pfn >= start_pfn; pfn -= PAGES_PER_SUBSECTION) { >+ if (unlikely(!pfn_valid(pfn))) > continue; > > if (unlikely(pfn_to_nid(pfn) != nid)) >@@ -373,7 +366,6 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, > unsigned long z = zone_end_pfn(zone); /* zone_end_pfn namespace clash */ > unsigned long zone_end_pfn = z; > unsigned long pfn; >- struct mem_section *ms; > int nid = zone_to_nid(zone); > > zone_span_writelock(zone); >@@ -410,10 +402,8 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, > * it check the zone has only hole or not. > */ > pfn = zone_start_pfn; >- for (; pfn < zone_end_pfn; pfn += PAGES_PER_SECTION) { >- ms = __pfn_to_section(pfn); >- >- if (unlikely(!valid_section(ms))) >+ for (; pfn < zone_end_pfn; pfn += PAGES_PER_SUBSECTION) { >+ if (unlikely(!pfn_valid(pfn))) > continue; > > if (page_zone(pfn_to_page(pfn)) != zone) >@@ -441,7 +431,6 @@ static void shrink_pgdat_span(struct pglist_data *pgdat, > unsigned long p = pgdat_end_pfn(pgdat); /* pgdat_end_pfn namespace clash */ > unsigned long pgdat_end_pfn = p; > unsigned long pfn; >- struct mem_section *ms; > int nid = pgdat->node_id; > > if (pgdat_start_pfn == start_pfn) { >@@ -478,10 +467,8 @@ static void shrink_pgdat_span(struct pglist_data *pgdat, > * has only hole or not. > */ > pfn = pgdat_start_pfn; >- for (; pfn < pgdat_end_pfn; pfn += PAGES_PER_SECTION) { >- ms = __pfn_to_section(pfn); >- >- if (unlikely(!valid_section(ms))) >+ for (; pfn < pgdat_end_pfn; pfn += PAGES_PER_SUBSECTION) { >+ if (unlikely(!pfn_valid(pfn))) > continue; > > if (pfn_to_nid(pfn) != nid) > >_______________________________________________ >Linux-nvdimm mailing list >Linux-nvdimm@lists.01.org >https://lists.01.org/mailman/listinfo/linux-nvdimm
On Mon, Jun 17, 2019 at 6:42 PM Wei Yang <richardw.yang@linux.intel.com> wrote: > > On Wed, Jun 05, 2019 at 02:58:04PM -0700, Dan Williams wrote: > >Sub-section hotplug support reduces the unit of operation of hotplug > >from section-sized-units (PAGES_PER_SECTION) to sub-section-sized units > >(PAGES_PER_SUBSECTION). Teach shrink_{zone,pgdat}_span() to consider > >PAGES_PER_SUBSECTION boundaries as the points where pfn_valid(), not > >valid_section(), can toggle. > > > >Cc: Michal Hocko <mhocko@suse.com> > >Cc: Vlastimil Babka <vbabka@suse.cz> > >Cc: Logan Gunthorpe <logang@deltatee.com> > >Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> > >Reviewed-by: Oscar Salvador <osalvador@suse.de> > >Signed-off-by: Dan Williams <dan.j.williams@intel.com> > >--- > > mm/memory_hotplug.c | 29 ++++++++--------------------- > > 1 file changed, 8 insertions(+), 21 deletions(-) > > > >diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > >index 7b963c2d3a0d..647859a1d119 100644 > >--- a/mm/memory_hotplug.c > >+++ b/mm/memory_hotplug.c > >@@ -318,12 +318,8 @@ static unsigned long find_smallest_section_pfn(int nid, struct zone *zone, > > unsigned long start_pfn, > > unsigned long end_pfn) > > { > >- struct mem_section *ms; > >- > >- for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SECTION) { > >- ms = __pfn_to_section(start_pfn); > >- > >- if (unlikely(!valid_section(ms))) > >+ for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SUBSECTION) { > >+ if (unlikely(!pfn_valid(start_pfn))) > > continue; > > Hmm, we change the granularity of valid section from SECTION to SUBSECTION. > But we didn't change the granularity of node id and zone information. > > For example, we found the node id of a pfn mismatch, we can skip the whole > section instead of a subsection. > > Maybe this is not a big deal. I don't see a problem.
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 7b963c2d3a0d..647859a1d119 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -318,12 +318,8 @@ static unsigned long find_smallest_section_pfn(int nid, struct zone *zone, unsigned long start_pfn, unsigned long end_pfn) { - struct mem_section *ms; - - for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SECTION) { - ms = __pfn_to_section(start_pfn); - - if (unlikely(!valid_section(ms))) + for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SUBSECTION) { + if (unlikely(!pfn_valid(start_pfn))) continue; if (unlikely(pfn_to_nid(start_pfn) != nid)) @@ -343,15 +339,12 @@ static unsigned long find_biggest_section_pfn(int nid, struct zone *zone, unsigned long start_pfn, unsigned long end_pfn) { - struct mem_section *ms; unsigned long pfn; /* pfn is the end pfn of a memory section. */ pfn = end_pfn - 1; - for (; pfn >= start_pfn; pfn -= PAGES_PER_SECTION) { - ms = __pfn_to_section(pfn); - - if (unlikely(!valid_section(ms))) + for (; pfn >= start_pfn; pfn -= PAGES_PER_SUBSECTION) { + if (unlikely(!pfn_valid(pfn))) continue; if (unlikely(pfn_to_nid(pfn) != nid)) @@ -373,7 +366,6 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, unsigned long z = zone_end_pfn(zone); /* zone_end_pfn namespace clash */ unsigned long zone_end_pfn = z; unsigned long pfn; - struct mem_section *ms; int nid = zone_to_nid(zone); zone_span_writelock(zone); @@ -410,10 +402,8 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, * it check the zone has only hole or not. */ pfn = zone_start_pfn; - for (; pfn < zone_end_pfn; pfn += PAGES_PER_SECTION) { - ms = __pfn_to_section(pfn); - - if (unlikely(!valid_section(ms))) + for (; pfn < zone_end_pfn; pfn += PAGES_PER_SUBSECTION) { + if (unlikely(!pfn_valid(pfn))) continue; if (page_zone(pfn_to_page(pfn)) != zone) @@ -441,7 +431,6 @@ static void shrink_pgdat_span(struct pglist_data *pgdat, unsigned long p = pgdat_end_pfn(pgdat); /* pgdat_end_pfn namespace clash */ unsigned long pgdat_end_pfn = p; unsigned long pfn; - struct mem_section *ms; int nid = pgdat->node_id; if (pgdat_start_pfn == start_pfn) { @@ -478,10 +467,8 @@ static void shrink_pgdat_span(struct pglist_data *pgdat, * has only hole or not. */ pfn = pgdat_start_pfn; - for (; pfn < pgdat_end_pfn; pfn += PAGES_PER_SECTION) { - ms = __pfn_to_section(pfn); - - if (unlikely(!valid_section(ms))) + for (; pfn < pgdat_end_pfn; pfn += PAGES_PER_SUBSECTION) { + if (unlikely(!pfn_valid(pfn))) continue; if (pfn_to_nid(pfn) != nid)
Sub-section hotplug support reduces the unit of operation of hotplug from section-sized-units (PAGES_PER_SECTION) to sub-section-sized units (PAGES_PER_SUBSECTION). Teach shrink_{zone,pgdat}_span() to consider PAGES_PER_SUBSECTION boundaries as the points where pfn_valid(), not valid_section(), can toggle. Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- mm/memory_hotplug.c | 29 ++++++++--------------------- 1 file changed, 8 insertions(+), 21 deletions(-)