[PATCH] metag: Drop show_mem() from mem_init()

From: James Hogan
Date: Fri Aug 05 2016 - 08:18:29 EST


The recent commit 599d0c954f91 ("mm, vmscan: move LRU lists to node"),
changed memory management code so that show_mem() is no longer safe to
call prior to setup_per_cpu_pageset(), as pgdat->per_cpu_nodestats will
still be NULL. This causes an oops on metag due to the call to
show_mem() from mem_init():

node_page_state_snapshot(...) + 0x48
pgdat_reclaimable(struct pglist_data * pgdat = 0x402517a0)
show_free_areas(unsigned int filter = 0) + 0x2cc
show_mem(unsigned int filter = 0) + 0x18
mem_init()
mm_init()
start_kernel() + 0x204

This wasn't a problem before with zone_reclaimable() as zone_pcp_init()
was already setting zone->pageset to &boot_pageset, via setup_arch() and
paging_init(), which happens before mm_init():

zone_pcp_init(...)
free_area_init_core(...) + 0x138
free_area_init_node(int nid = 0, ...) + 0x1a0
free_area_init_nodes(...) + 0x440
paging_init(unsigned long mem_end = 0x4fe00000) + 0x378
setup_arch(char ** cmdline_p = 0x4024e038) + 0x2b8
start_kernel() + 0x54

No other arches appear to call show_mem() during boot, and it doesn't
really add much value to the log, so lets just drop it from mem_init().

Signed-off-by: James Hogan <james.hogan@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: linux-metag@xxxxxxxxxxxxxxx
---
arch/metag/mm/init.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/arch/metag/mm/init.c b/arch/metag/mm/init.c
index 11fa51c89617..c0ec116b3993 100644
--- a/arch/metag/mm/init.c
+++ b/arch/metag/mm/init.c
@@ -390,7 +390,6 @@ void __init mem_init(void)

free_all_bootmem();
mem_init_print_info(NULL);
- show_mem(0);
}

void free_initmem(void)
--
2.9.2