On Thu, 28 Jan 2021, David Hildenbrand wrote:
quoted hunk ↗ jump to hunk
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 7758486097f9..957680db41fa 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1650,6 +1650,11 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
zone->spanned_pages,
zone->present_pages,
zone_managed_pages(zone));
+#ifdef CONFIG_CMA
+ seq_printf(m,
+ "\n cma %lu",
+ zone->cma_pages);
+#endif
seq_printf(m,
"\n protection: (%ld",
Hmm, not sure about this. If cma is only printed for CONFIG_CMA, we can't
distinguish between (1) a kernel without your patch without including some
version checking and (2) a kernel without CONFIG_CMA enabled. IOW,
"cma 0" carries value: we know immediately that we do not have any CMA
pages on this zone, period.
/proc/zoneinfo is also not known for its conciseness so I think printing
"cma 0" even for !CONFIG_CMA is helpful :)
I think this #ifdef should be removed and it should call into a
zone_cma_pages(struct zone *zone) which returns 0UL if disabled.