Messages in this thread Patch in this message | | | Date | Mon, 15 Dec 2008 15:34:39 +0100 | From | Heiko Carstens <> | Subject | [PATCH/RESEND 2/2] sched: re-add missing arch_update_cpu_topology call |
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From: Heiko Carstens <heiko.carstens@de.ibm.com>
arch_reinit_sched_domains used to call arch_update_cpu_topology via arch_init_sched_domains. This call got lost with e761b7725234276a802322549cee5255305a0930 ("cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment (take 2)".
So we might end up with outdated and missing cpus in the cpu core maps (architecture used to call arch_reinit_sched_domains if cpu topology changed).
This adds a call to arch_update_cpu_topology in partition_sched_domains which gets called whenever scheduling domains get updated. Which is what is supposed to happen when cpu topology changes.
Since arch_update_cpu_topology returns 0 if the cpu topology didn't change this is a NOP for all architectures but s390 (currently).
If arch_update_cpu_topology returns 1 this causes all scheduling domains to be destroyed and rebuilt.
Cc: Max Krasnyansky <maxk@qualcomm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> --- kernel/sched.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
Index: linux-2.6/kernel/sched.c =================================================================== --- linux-2.6.orig/kernel/sched.c +++ linux-2.6/kernel/sched.c @@ -7813,17 +7813,21 @@ void partition_sched_domains(int ndoms_n struct sched_domain_attr *dattr_new) { int i, j, n; + int top_changed; mutex_lock(&sched_domains_mutex); /* always unregister in case we don't destroy any domains */ unregister_sched_domain_sysctl(); + /* Let architecture update cpu core mappings. */ + top_changed = arch_update_cpu_topology(); + n = doms_new ? ndoms_new : 0; /* Destroy deleted domains */ for (i = 0; i < ndoms_cur; i++) { - for (j = 0; j < n; j++) { + for (j = 0; j < n && !top_changed; j++) { if (cpus_equal(doms_cur[i], doms_new[j]) && dattrs_equal(dattr_cur, i, dattr_new, j)) goto match1; @@ -7843,7 +7847,7 @@ match1: /* Build new domains */ for (i = 0; i < ndoms_new; i++) { - for (j = 0; j < ndoms_cur; j++) { + for (j = 0; j < ndoms_cur && !top_changed; j++) { if (cpus_equal(doms_new[i], doms_cur[j]) && dattrs_equal(dattr_new, i, dattr_cur, j)) goto match2; --
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