From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754405Ab3F0T5K (ORCPT ); Thu, 27 Jun 2013 15:57:10 -0400 Received: from e23smtp05.au.ibm.com ([202.81.31.147]:46773 "EHLO e23smtp05.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754373Ab3F0T47 (ORCPT ); Thu, 27 Jun 2013 15:56:59 -0400 From: "Srivatsa S. Bhat" Subject: [PATCH v3 06/45] CPU hotplug: Sprinkle debugging checks to catch locking bugs To: tglx@linutronix.de, peterz@infradead.org, tj@kernel.org, oleg@redhat.com, paulmck@linux.vnet.ibm.com, rusty@rustcorp.com.au, mingo@kernel.org, akpm@linux-foundation.org, namhyung@kernel.org, walken@google.com, vincent.guittot@linaro.org, laijs@cn.fujitsu.com, David.Laight@aculab.com Cc: rostedt@goodmis.org, wangyun@linux.vnet.ibm.com, xiaoguangrong@linux.vnet.ibm.com, sbw@mit.edu, fweisbec@gmail.com, zhong@linux.vnet.ibm.com, nikunj@linux.vnet.ibm.com, srivatsa.bhat@linux.vnet.ibm.com, linux-pm@vger.kernel.org, linux-arch@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Rusty Russell , Alex Shi , KOSAKI Motohiro , Tejun Heo , Andrew Morton , Joonsoo Kim , "Srivatsa S. Bhat" Date: Fri, 28 Jun 2013 01:23:31 +0530 Message-ID: <20130627195331.29830.74970.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20130627195136.29830.10445.stgit@srivatsabhat.in.ibm.com> References: <20130627195136.29830.10445.stgit@srivatsabhat.in.ibm.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13062719-1396-0000-0000-0000032F2A56 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Cc: Alex Shi Cc: KOSAKI Motohiro Cc: Tejun Heo Cc: Andrew Morton Cc: Joonsoo Kim Signed-off-by: Srivatsa S. Bhat --- 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;