free_area_init_node() calls calculate_node_totalpages() and
free_area_init_core(). The former to get node's {spanned,present}_pages,
and the latter to calculate, among other things, how many pages per zone
we spent on memmap_pages, which is used to substract zone's free pages.
On memoryless-nodes, it is pointless to perform such a bunch of work, so
make sure we skip the calculations when having a node or empty zone.
Signed-off-by: Oscar Salvador <[email protected]>
---
mm/page_alloc.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e008a3df0485..2b9b2422ba32 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -7361,6 +7361,10 @@ static void __init calculate_node_totalpages(struct pglist_data *pgdat,
unsigned long realtotalpages = 0, totalpages = 0;
enum zone_type i;
+ /* Skip calculation for memoryless nodes */
+ if (pgdat_is_empty(pgdat))
+ goto no_pages;
+
for (i = 0; i < MAX_NR_ZONES; i++) {
struct zone *zone = pgdat->node_zones + i;
unsigned long zone_start_pfn, zone_end_pfn;
@@ -7393,6 +7397,7 @@ static void __init calculate_node_totalpages(struct pglist_data *pgdat,
realtotalpages += real_size;
}
+no_pages:
pgdat->node_spanned_pages = totalpages;
pgdat->node_present_pages = realtotalpages;
pr_debug("On node %d totalpages: %lu\n", pgdat->node_id, realtotalpages);
@@ -7610,6 +7615,12 @@ static void __init free_area_init_core(struct pglist_data *pgdat)
size = zone->spanned_pages;
freesize = zone->present_pages;
+ /* No pages? Nothing to calculate then. */
+ if (!size) {
+ zone_init_internals(zone, j, nid, 0);
+ continue;
+ }
+
/*
* Adjust freesize so that it accounts for how much memory
* is used by this zone for memmap. This affects the watermark
@@ -7647,9 +7658,6 @@ static void __init free_area_init_core(struct pglist_data *pgdat)
*/
zone_init_internals(zone, j, nid, freesize);
- if (!size)
- continue;
-
set_pageblock_order();
setup_usemap(zone);
init_currently_empty_zone(zone, zone->zone_start_pfn, size);
@@ -7730,7 +7738,7 @@ static void __init free_area_init_node(int nid)
pgdat->node_start_pfn = start_pfn;
pgdat->per_cpu_nodestats = NULL;
- if (start_pfn != end_pfn) {
+ if (!pgdat_is_empty(pgdat)) {
pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
(u64)start_pfn << PAGE_SHIFT,
end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0);
--
2.35.3
On 21.06.22 06:17, Oscar Salvador wrote:
> free_area_init_node() calls calculate_node_totalpages() and
> free_area_init_core(). The former to get node's {spanned,present}_pages,
> and the latter to calculate, among other things, how many pages per zone
> we spent on memmap_pages, which is used to substract zone's free pages.
>
> On memoryless-nodes, it is pointless to perform such a bunch of work, so
> make sure we skip the calculations when having a node or empty zone.
>
> Signed-off-by: Oscar Salvador <[email protected]>
> ---
> mm/page_alloc.c | 16 ++++++++++++----
> 1 file changed, 12 insertions(+), 4 deletions(-)
>
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index e008a3df0485..2b9b2422ba32 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -7361,6 +7361,10 @@ static void __init calculate_node_totalpages(struct pglist_data *pgdat,
> unsigned long realtotalpages = 0, totalpages = 0;
> enum zone_type i;
>
> + /* Skip calculation for memoryless nodes */
> + if (pgdat_is_empty(pgdat))
> + goto no_pages;
> +
> for (i = 0; i < MAX_NR_ZONES; i++) {
> struct zone *zone = pgdat->node_zones + i;
> unsigned long zone_start_pfn, zone_end_pfn;
> @@ -7393,6 +7397,7 @@ static void __init calculate_node_totalpages(struct pglist_data *pgdat,
> realtotalpages += real_size;
> }
>
> +no_pages:
> pgdat->node_spanned_pages = totalpages;
> pgdat->node_present_pages = realtotalpages;
> pr_debug("On node %d totalpages: %lu\n", pgdat->node_id, realtotalpages);
> @@ -7610,6 +7615,12 @@ static void __init free_area_init_core(struct pglist_data *pgdat)
> size = zone->spanned_pages;
> freesize = zone->present_pages;
>
> + /* No pages? Nothing to calculate then. */
> + if (!size) {
> + zone_init_internals(zone, j, nid, 0);
> + continue;
> + }
> +
> /*
> * Adjust freesize so that it accounts for how much memory
> * is used by this zone for memmap. This affects the watermark
> @@ -7647,9 +7658,6 @@ static void __init free_area_init_core(struct pglist_data *pgdat)
> */
> zone_init_internals(zone, j, nid, freesize);
>
> - if (!size)
> - continue;
> -
> set_pageblock_order();
> setup_usemap(zone);
> init_currently_empty_zone(zone, zone->zone_start_pfn, size);
> @@ -7730,7 +7738,7 @@ static void __init free_area_init_node(int nid)
> pgdat->node_start_pfn = start_pfn;
> pgdat->per_cpu_nodestats = NULL;
>
> - if (start_pfn != end_pfn) {
> + if (!pgdat_is_empty(pgdat)) {
> pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
> (u64)start_pfn << PAGE_SHIFT,
> end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0);
It's worth noting that the check in pgdat_is_empty() is slightly
different. I *think* it doesn't matter in practice, yet I wonder if we
should simply fixup (currently unused) pgdat_is_empty().
Anyhow
Reviewed-by: David Hildenbrand <[email protected]>
--
Thanks,
David / dhildenb
On Tue, Jun 21, 2022 at 09:44:47AM +0200, David Hildenbrand wrote:
>
>
> It's worth noting that the check in pgdat_is_empty() is slightly
> different. I *think* it doesn't matter in practice, yet I wonder if we
> should simply fixup (currently unused) pgdat_is_empty().
I guess we could change it to
static inline bool pgdat_is_empty(pg_data_t *pgdat)
{
return node_start_pfn(pgdat->node_id) == node_end_pfn(pgdat->node_id)
}
? And maybe even rename it to to node_is_empty (not sure why but I tend to like
that more than pgdat)
I could squeeze a "fixup" patch for that before this one.
>
> Anyhow
>
> Reviewed-by: David Hildenbrand <[email protected]>
Thanks!
--
Oscar Salvador
SUSE Labs
On Wed, Jun 22, 2022 at 05:47:22AM +0200, Oscar Salvador wrote:
> On Tue, Jun 21, 2022 at 09:44:47AM +0200, David Hildenbrand wrote:
> >
> >
> > It's worth noting that the check in pgdat_is_empty() is slightly
> > different. I *think* it doesn't matter in practice, yet I wonder if we
> > should simply fixup (currently unused) pgdat_is_empty().
>
> I guess we could change it to
>
> static inline bool pgdat_is_empty(pg_data_t *pgdat)
> {
> return node_start_pfn(pgdat->node_id) == node_end_pfn(pgdat->node_id)
> }
>
> ? And maybe even rename it to to node_is_empty (not sure why but I tend to like
At least I like this name (node_is_empty) as well.
Thanks.
> that more than pgdat)
>
> I could squeeze a "fixup" patch for that before this one.
>
> >
> > Anyhow
> >
> > Reviewed-by: David Hildenbrand <[email protected]>
>
> Thanks!
>
>
> --
> Oscar Salvador
> SUSE Labs
>
On 22.06.22 05:56, Muchun Song wrote:
> On Wed, Jun 22, 2022 at 05:47:22AM +0200, Oscar Salvador wrote:
>> On Tue, Jun 21, 2022 at 09:44:47AM +0200, David Hildenbrand wrote:
>>>
>>>
>>> It's worth noting that the check in pgdat_is_empty() is slightly
>>> different. I *think* it doesn't matter in practice, yet I wonder if we
>>> should simply fixup (currently unused) pgdat_is_empty().
>>
>> I guess we could change it to
>>
>> static inline bool pgdat_is_empty(pg_data_t *pgdat)
>> {
>> return node_start_pfn(pgdat->node_id) == node_end_pfn(pgdat->node_id)
>> }
>>
>> ? And maybe even rename it to to node_is_empty (not sure why but I tend to like
>
> At least I like this name (node_is_empty) as well.
>
Let's try keeping it consistent. I think node_is_empty() might indicate
that we're punching in a node id instead of a pgdat.
--
Thanks,
David / dhildenb
On Wed, Jun 22, 2022 at 10:31:12AM +0200, David Hildenbrand wrote:
> On 22.06.22 05:56, Muchun Song wrote:
> > On Wed, Jun 22, 2022 at 05:47:22AM +0200, Oscar Salvador wrote:
> >> On Tue, Jun 21, 2022 at 09:44:47AM +0200, David Hildenbrand wrote:
> >>>
> >>>
> >>> It's worth noting that the check in pgdat_is_empty() is slightly
> >>> different. I *think* it doesn't matter in practice, yet I wonder if we
> >>> should simply fixup (currently unused) pgdat_is_empty().
> >>
> >> I guess we could change it to
> >>
> >> static inline bool pgdat_is_empty(pg_data_t *pgdat)
> >> {
> >> return node_start_pfn(pgdat->node_id) == node_end_pfn(pgdat->node_id)
> >> }
> >>
> >> ? And maybe even rename it to to node_is_empty (not sure why but I tend to like
> >
> > At least I like this name (node_is_empty) as well.
> >
>
> Let's try keeping it consistent. I think node_is_empty() might indicate
> that we're punching in a node id instead of a pgdat.
>
I suspect Oscar will change the argument to "nid" as well, like:
static inline bool node_is_empty(int nid)
{
return node_start_pfn(nid) == node_end_pfn(nid);
}
Does this look good?
Thanks.
>
> --
> Thanks,
>
> David / dhildenb
>
>
On 22.06.22 10:54, Muchun Song wrote:
> On Wed, Jun 22, 2022 at 10:31:12AM +0200, David Hildenbrand wrote:
>> On 22.06.22 05:56, Muchun Song wrote:
>>> On Wed, Jun 22, 2022 at 05:47:22AM +0200, Oscar Salvador wrote:
>>>> On Tue, Jun 21, 2022 at 09:44:47AM +0200, David Hildenbrand wrote:
>>>>>
>>>>>
>>>>> It's worth noting that the check in pgdat_is_empty() is slightly
>>>>> different. I *think* it doesn't matter in practice, yet I wonder if we
>>>>> should simply fixup (currently unused) pgdat_is_empty().
>>>>
>>>> I guess we could change it to
>>>>
>>>> static inline bool pgdat_is_empty(pg_data_t *pgdat)
>>>> {
>>>> return node_start_pfn(pgdat->node_id) == node_end_pfn(pgdat->node_id)
>>>> }
>>>>
>>>> ? And maybe even rename it to to node_is_empty (not sure why but I tend to like
>>>
>>> At least I like this name (node_is_empty) as well.
>>>
>>
>> Let's try keeping it consistent. I think node_is_empty() might indicate
>> that we're punching in a node id instead of a pgdat.
>>
>
> I suspect Oscar will change the argument to "nid" as well, like:
>
> static inline bool node_is_empty(int nid)
> {
> return node_start_pfn(nid) == node_end_pfn(nid);
> }
>
> Does this look good?
Then we have to lookup the pgdat multiple times for (IMHO) no real
compelling reason.
--
Thanks,
David / dhildenb