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authorRobert Richter <robert.richter@amd.com>2011-01-03 12:15:14 +0100
committerIngo Molnar <mingo@elte.hu>2011-01-03 13:01:40 +0100
commitc7c25802b39c443b3745cfa973dc49a97a3491f8 (patch)
treec12d44f18788da6574d8df468861766b954095e8 /arch/x86/oprofile
parent551423748a4eba55f2eb0fc250d757986471f187 (diff)
downloadlinux-2.6.38-lt-ux500-c7c25802b39c443b3745cfa973dc49a97a3491f8.tar.gz
arch/x86/oprofile/op_model_amd.c: Perform initialisation on a single CPU
Disable preemption in init_ibs(). The function only checks the ibs capabilities and sets up pci devices (if necessary). It runs only on one cpu but operates with the local APIC and some MSRs, thus it is better to disable preemption. [ 7.034377] BUG: using smp_processor_id() in preemptible [00000000] code: modprobe/483 [ 7.034385] caller is setup_APIC_eilvt+0x155/0x180 [ 7.034389] Pid: 483, comm: modprobe Not tainted 2.6.37-rc1-20101110+ #1 [ 7.034392] Call Trace: [ 7.034400] [<ffffffff812a2b72>] debug_smp_processor_id+0xd2/0xf0 [ 7.034404] [<ffffffff8101e985>] setup_APIC_eilvt+0x155/0x180 [ ... ] Addresses https://bugzilla.kernel.org/show_bug.cgi?id=22812 Reported-by: <atswartz@gmail.com> Signed-off-by: Robert Richter <robert.richter@amd.com> Cc: oprofile-list@lists.sourceforge.net <oprofile-list@lists.sourceforge.net> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Dan Carpenter <error27@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: <stable@kernel.org> [2.6.37.x] LKML-Reference: <20110103111514.GM4739@erda.amd.com> [ small cleanups ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/oprofile')
-rw-r--r--arch/x86/oprofile/op_model_amd.c24
1 files changed, 16 insertions, 8 deletions
diff --git a/arch/x86/oprofile/op_model_amd.c b/arch/x86/oprofile/op_model_amd.c
index a011bcc0f94..7d90d47655b 100644
--- a/arch/x86/oprofile/op_model_amd.c
+++ b/arch/x86/oprofile/op_model_amd.c
@@ -630,21 +630,29 @@ static int __init_ibs_nmi(void)
return 0;
}
-/* initialize the APIC for the IBS interrupts if available */
+/*
+ * check and reserve APIC extended interrupt LVT offset for IBS if
+ * available
+ *
+ * init_ibs() preforms implicitly cpu-local operations, so pin this
+ * thread to its current CPU
+ */
+
static void init_ibs(void)
{
- ibs_caps = get_ibs_caps();
+ preempt_disable();
+ ibs_caps = get_ibs_caps();
if (!ibs_caps)
- return;
+ goto out;
- if (__init_ibs_nmi()) {
+ if (__init_ibs_nmi() < 0)
ibs_caps = 0;
- return;
- }
+ else
+ printk(KERN_INFO "oprofile: AMD IBS detected (0x%08x)\n", ibs_caps);
- printk(KERN_INFO "oprofile: AMD IBS detected (0x%08x)\n",
- (unsigned)ibs_caps);
+out:
+ preempt_enable();
}
static int (*create_arch_files)(struct super_block *sb, struct dentry *root);