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Message-ID: <20130623133909.19094.18155.stgit@srivatsabhat.in.ibm.com>
Date: Sun, 23 Jun 2013 19:09:15 +0530
From: "Srivatsa S. Bhat" <srivatsa.bhat@...ux.vnet.ibm.com>
To: tglx@...utronix.de, peterz@...radead.org, tj@...nel.org,
oleg@...hat.com, paulmck@...ux.vnet.ibm.com, rusty@...tcorp.com.au,
mingo@...nel.org, akpm@...ux-foundation.org, namhyung@...nel.org,
walken@...gle.com, vincent.guittot@...aro.org, laijs@...fujitsu.com
Cc: rostedt@...dmis.org, wangyun@...ux.vnet.ibm.com,
xiaoguangrong@...ux.vnet.ibm.com, sbw@....edu, fweisbec@...il.com,
zhong@...ux.vnet.ibm.com, nikunj@...ux.vnet.ibm.com,
srivatsa.bhat@...ux.vnet.ibm.com, linux-pm@...r.kernel.org,
linux-arch@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
Rusty Russell <rusty@...tcorp.com.au>,
Alex Shi <alex.shi@...el.com>,
KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>,
Tejun Heo <tj@...nel.org>,
Andrew Morton <akpm@...ux-foundation.org>,
Joonsoo Kim <js1304@...il.com>
Subject: [PATCH 06/45] CPU hotplug: Sprinkle debugging checks to catch locking
bugs
Now that we have a debug infrastructure in place to detect cases where
get/put_online_cpus_atomic() had to be used, add these checks at the
right spots to help catch places where we missed converting to the new
APIs.
Cc: Rusty Russell <rusty@...tcorp.com.au>
Cc: Alex Shi <alex.shi@...el.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>
Cc: Tejun Heo <tj@...nel.org>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: Joonsoo Kim <js1304@...il.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@...ux.vnet.ibm.com>
---
include/linux/cpumask.h | 47 +++++++++++++++++++++++++++++++++++++++++++++--
lib/cpumask.c | 8 ++++++++
2 files changed, 53 insertions(+), 2 deletions(-)
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index 9197ca4..06d2c36 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -169,6 +169,7 @@ static inline unsigned int cpumask_any_but(const struct cpumask *mask,
*/
static inline unsigned int cpumask_first(const struct cpumask *srcp)
{
+ check_hotplug_safe_cpumask(srcp);
return find_first_bit(cpumask_bits(srcp), nr_cpumask_bits);
}
@@ -184,6 +185,8 @@ static inline unsigned int cpumask_next(int n, const struct cpumask *srcp)
/* -1 is a legal arg here. */
if (n != -1)
cpumask_check(n);
+
+ check_hotplug_safe_cpumask(srcp);
return find_next_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1);
}
@@ -199,6 +202,8 @@ static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
/* -1 is a legal arg here. */
if (n != -1)
cpumask_check(n);
+
+ check_hotplug_safe_cpumask(srcp);
return find_next_zero_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1);
}
@@ -288,8 +293,15 @@ static inline void cpumask_clear_cpu(int cpu, struct cpumask *dstp)
*
* No static inline type checking - see Subtlety (1) above.
*/
-#define cpumask_test_cpu(cpu, cpumask) \
- test_bit(cpumask_check(cpu), cpumask_bits((cpumask)))
+#define cpumask_test_cpu(cpu, cpumask) \
+({ \
+ int __ret; \
+ \
+ check_hotplug_safe_cpu(cpu, cpumask); \
+ __ret = test_bit(cpumask_check(cpu), \
+ cpumask_bits((cpumask))); \
+ __ret; \
+})
/**
* cpumask_test_and_set_cpu - atomically test and set a cpu in a cpumask
@@ -349,6 +361,9 @@ static inline int cpumask_and(struct cpumask *dstp,
const struct cpumask *src1p,
const struct cpumask *src2p)
{
+ check_hotplug_safe_cpumask(src1p);
+ check_hotplug_safe_cpumask(src2p);
+
return bitmap_and(cpumask_bits(dstp), cpumask_bits(src1p),
cpumask_bits(src2p), nr_cpumask_bits);
}
@@ -362,6 +377,9 @@ static inline int cpumask_and(struct cpumask *dstp,
static inline void cpumask_or(struct cpumask *dstp, const struct cpumask *src1p,
const struct cpumask *src2p)
{
+ check_hotplug_safe_cpumask(src1p);
+ check_hotplug_safe_cpumask(src2p);
+
bitmap_or(cpumask_bits(dstp), cpumask_bits(src1p),
cpumask_bits(src2p), nr_cpumask_bits);
}
@@ -376,6 +394,9 @@ static inline void cpumask_xor(struct cpumask *dstp,
const struct cpumask *src1p,
const struct cpumask *src2p)
{
+ check_hotplug_safe_cpumask(src1p);
+ check_hotplug_safe_cpumask(src2p);
+
bitmap_xor(cpumask_bits(dstp), cpumask_bits(src1p),
cpumask_bits(src2p), nr_cpumask_bits);
}
@@ -392,6 +413,9 @@ static inline int cpumask_andnot(struct cpumask *dstp,
const struct cpumask *src1p,
const struct cpumask *src2p)
{
+ check_hotplug_safe_cpumask(src1p);
+ check_hotplug_safe_cpumask(src2p);
+
return bitmap_andnot(cpumask_bits(dstp), cpumask_bits(src1p),
cpumask_bits(src2p), nr_cpumask_bits);
}
@@ -404,6 +428,8 @@ static inline int cpumask_andnot(struct cpumask *dstp,
static inline void cpumask_complement(struct cpumask *dstp,
const struct cpumask *srcp)
{
+ check_hotplug_safe_cpumask(srcp);
+
bitmap_complement(cpumask_bits(dstp), cpumask_bits(srcp),
nr_cpumask_bits);
}
@@ -416,6 +442,9 @@ static inline void cpumask_complement(struct cpumask *dstp,
static inline bool cpumask_equal(const struct cpumask *src1p,
const struct cpumask *src2p)
{
+ check_hotplug_safe_cpumask(src1p);
+ check_hotplug_safe_cpumask(src2p);
+
return bitmap_equal(cpumask_bits(src1p), cpumask_bits(src2p),
nr_cpumask_bits);
}
@@ -428,6 +457,10 @@ static inline bool cpumask_equal(const struct cpumask *src1p,
static inline bool cpumask_intersects(const struct cpumask *src1p,
const struct cpumask *src2p)
{
+
+ check_hotplug_safe_cpumask(src1p);
+ check_hotplug_safe_cpumask(src2p);
+
return bitmap_intersects(cpumask_bits(src1p), cpumask_bits(src2p),
nr_cpumask_bits);
}
@@ -442,6 +475,9 @@ static inline bool cpumask_intersects(const struct cpumask *src1p,
static inline int cpumask_subset(const struct cpumask *src1p,
const struct cpumask *src2p)
{
+ check_hotplug_safe_cpumask(src1p);
+ check_hotplug_safe_cpumask(src2p);
+
return bitmap_subset(cpumask_bits(src1p), cpumask_bits(src2p),
nr_cpumask_bits);
}
@@ -470,6 +506,12 @@ static inline bool cpumask_full(const struct cpumask *srcp)
*/
static inline unsigned int cpumask_weight(const struct cpumask *srcp)
{
+ /*
+ * Often, we just want to have a rough estimate of the number of
+ * online CPUs, without going to the trouble of synchronizing with
+ * CPU hotplug. So don't invoke check_hotplug_safe_cpumask() here.
+ */
+
return bitmap_weight(cpumask_bits(srcp), nr_cpumask_bits);
}
@@ -507,6 +549,7 @@ static inline void cpumask_shift_left(struct cpumask *dstp,
static inline void cpumask_copy(struct cpumask *dstp,
const struct cpumask *srcp)
{
+ check_hotplug_safe_cpumask(srcp);
bitmap_copy(cpumask_bits(dstp), cpumask_bits(srcp), nr_cpumask_bits);
}
diff --git a/lib/cpumask.c b/lib/cpumask.c
index d327b87..481df57 100644
--- a/lib/cpumask.c
+++ b/lib/cpumask.c
@@ -7,12 +7,14 @@
int __first_cpu(const cpumask_t *srcp)
{
+ check_hotplug_safe_cpumask(srcp);
return min_t(int, NR_CPUS, find_first_bit(srcp->bits, NR_CPUS));
}
EXPORT_SYMBOL(__first_cpu);
int __next_cpu(int n, const cpumask_t *srcp)
{
+ check_hotplug_safe_cpumask(srcp);
return min_t(int, NR_CPUS, find_next_bit(srcp->bits, NR_CPUS, n+1));
}
EXPORT_SYMBOL(__next_cpu);
@@ -20,6 +22,7 @@ EXPORT_SYMBOL(__next_cpu);
#if NR_CPUS > 64
int __next_cpu_nr(int n, const cpumask_t *srcp)
{
+ check_hotplug_safe_cpumask(srcp);
return min_t(int, nr_cpu_ids,
find_next_bit(srcp->bits, nr_cpu_ids, n+1));
}
@@ -37,6 +40,9 @@ EXPORT_SYMBOL(__next_cpu_nr);
int cpumask_next_and(int n, const struct cpumask *src1p,
const struct cpumask *src2p)
{
+ check_hotplug_safe_cpumask(src1p);
+ check_hotplug_safe_cpumask(src2p);
+
while ((n = cpumask_next(n, src1p)) < nr_cpu_ids)
if (cpumask_test_cpu(n, src2p))
break;
@@ -57,6 +63,8 @@ int cpumask_any_but(const struct cpumask *mask, unsigned int cpu)
unsigned int i;
cpumask_check(cpu);
+ check_hotplug_safe_cpumask(mask);
+
for_each_cpu(i, mask)
if (i != cpu)
break;
--
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