From 1044d6d19d23ef6fc8afe808ac8f8a9a4dc827ce Mon Sep 17 00:00:00 2001 From: Robert Richter Date: Mon, 3 Jan 2011 12:15:14 +0100 Subject: [PATCH] arch/x86/oprofile/op_model_amd.c: Perform initialisation on a single CPU commit c7c25802b39c443b3745cfa973dc49a97a3491f8 upstream. 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] [] debug_smp_processor_id+0xd2/0xf0 [ 7.034404] [] setup_APIC_eilvt+0x155/0x180 [ ... ] Addresses https://bugzilla.kernel.org/show_bug.cgi?id=22812 Reported-by: Signed-off-by: Robert Richter Cc: oprofile-list@lists.sourceforge.net Cc: Peter Zijlstra Cc: Frederic Weisbecker Cc: Rafael J. Wysocki Cc: Dan Carpenter Cc: Andrew Morton LKML-Reference: <20110103111514.GM4739@erda.amd.com> [ small cleanups ] Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/oprofile/op_model_amd.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/arch/x86/oprofile/op_model_amd.c b/arch/x86/oprofile/op_model_amd.c index b67a6b5aa8d4..42623310c968 100644 --- a/arch/x86/oprofile/op_model_amd.c +++ b/arch/x86/oprofile/op_model_amd.c @@ -484,21 +484,29 @@ 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); -- 2.39.5