Messages in this thread | | | Date | Wed, 13 May 2009 10:43:48 -0700 | From | Yinghai Lu <> | Subject | Re: [PATCH] x86: fix system without memory on node0 |
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Jack Steiner wrote: > On Tue, May 12, 2009 at 06:34:31PM -0700, Yinghai Lu wrote: >> Jack found that crash with doesn't have memory on node0. >> >> it turns out with per_cpu changeset, node_number for BSP will be alway 0, >> and it is consistent to cpu_to_node() that is to near node already. >> aka when numa_set_node() for node0 is called early before per_cpu area is >> setup >> >> try to set the node_number for boot cpu, after we get per_cpu area setup. >> >> [ Impact: fix crashing on memoryless node 0] >> >> Reported-by: Jack Steiner <steiner@sgi.com> >> Signed-off-by: Yinghai Lu <yinghai@kernel.org> >> >> --- >> arch/x86/kernel/setup_percpu.c | 8 ++++++++ >> 1 file changed, 8 insertions(+) >> >> Index: linux-2.6/arch/x86/kernel/setup_percpu.c >> =================================================================== >> --- linux-2.6.orig/arch/x86/kernel/setup_percpu.c >> +++ linux-2.6/arch/x86/kernel/setup_percpu.c >> @@ -423,6 +423,14 @@ void __init setup_per_cpu_areas(void) >> early_per_cpu_ptr(x86_cpu_to_node_map) = NULL; >> #endif >> >> +#if defined(CONFIG_X86_64) && defined(CONFIG_NUMA) >> + /* >> + * make sure boot cpu node_number is right, when boot cpu is on the >> + * node that doesn't have mem installed >> + */ >> + per_cpu(node_number, boot_cpu_id) = cpu_to_node(boot_cpu_id); >> +#endif >> + >> /* Setup node to cpumask map */ >> setup_node_to_cpumask_map(); >> > > With the patch above PLUS the patch below, I verified that all of our strange > configurations boot to shell prompt & run simple commands. There are certainly > some corner cases that have not been tested. > > Note that both patches are required. The system panics in early boot if either > patch is omitted. > > --- > > > Ignore offline nodes when building the zone lists. This > fix is needed to support configurations that hax PXMs with > cpus but no memory. > > > Signed-off-by: Jack Steiner <steiner@sgi.com> > > > --- > mm/page_alloc.c | 2 ++ > 1 file changed, 2 insertions(+) > > Index: linux/mm/page_alloc.c > =================================================================== > --- linux.orig/mm/page_alloc.c 2009-05-12 17:06:59.000000000 -0500 > +++ linux/mm/page_alloc.c 2009-05-13 09:54:09.000000000 -0500 > @@ -2370,6 +2370,8 @@ static void build_zonelists(pg_data_t *p > * If another node is sufficiently far away then it is better > * to reclaim pages in a zone before going off node. > */ > + if (!node_online(node)) > + continue; > if (distance > RECLAIM_DISTANCE) > zone_reclaim_mode = 1; >
that means that node_states[N_HIGH_MEMORY] is still not right.
and it should be done by /* * early_calculate_totalpages() * Sum pages in active regions for movable zone. * Populate N_HIGH_MEMORY for calculating usable_nodes. */ static unsigned long __init early_calculate_totalpages(void) { int i; unsigned long totalpages = 0;
for (i = 0; i < nr_nodemap_entries; i++) { unsigned long pages = early_node_map[i].end_pfn - early_node_map[i].start_pfn; totalpages += pages; if (pages) node_set_state(early_node_map[i].nid, N_HIGH_MEMORY); } return totalpages; }
also
void __init free_area_init_nodes(unsigned long *max_zone_pfn) ...
somehow that is broken?
YH
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