[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20221003153420.285896-4-vschneid@redhat.com>
Date: Mon, 3 Oct 2022 16:34:18 +0100
From: Valentin Schneider <vschneid@...hat.com>
To: linux-block@...r.kernel.org, linux-kernel@...r.kernel.org
Cc: Jens Axboe <axboe@...nel.dk>, Yury Norov <yury.norov@...il.com>,
Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
Rasmus Villemoes <linux@...musvillemoes.dk>,
Ingo Molnar <mingo@...hat.com>,
Peter Zijlstra <peterz@...radead.org>,
Juri Lelli <juri.lelli@...hat.com>,
Vincent Guittot <vincent.guittot@...aro.org>,
Dietmar Eggemann <dietmar.eggemann@....com>,
Steven Rostedt <rostedt@...dmis.org>,
Ben Segall <bsegall@...gle.com>, Mel Gorman <mgorman@...e.de>,
Daniel Bristot de Oliveira <bristot@...hat.com>
Subject: [PATCH bitmap-for-next 3/5] cpumask: Introduce for_each_cpu_andnot()
for_each_cpu_and() is very convenient as it saves having to allocate a
temporary cpumask to store the result of cpumask_and(). The same issue
applies to cpumask_andnot() which doesn't actually need temporary storage
for iteration purposes.
Following what has been done for for_each_cpu_and(), introduce
for_each_cpu_andnot().
Signed-off-by: Valentin Schneider <vschneid@...hat.com>
---
include/linux/cpumask.h | 18 ++++++++++++++++++
include/linux/find.h | 5 +++++
2 files changed, 23 insertions(+)
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index 286804bfe3b7..2f065ad97541 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -306,6 +306,24 @@ unsigned int __pure cpumask_next_wrap(int n, const struct cpumask *mask, int sta
#define for_each_cpu_and(cpu, mask1, mask2) \
for_each_and_bit(cpu, cpumask_bits(mask1), cpumask_bits(mask2), nr_cpumask_bits)
+/**
+ * for_each_cpu_andnot - iterate over every cpu present in one mask, excluding
+ * those present in another.
+ * @cpu: the (optionally unsigned) integer iterator
+ * @mask1: the first cpumask pointer
+ * @mask2: the second cpumask pointer
+ *
+ * This saves a temporary CPU mask in many places. It is equivalent to:
+ * struct cpumask tmp;
+ * cpumask_andnot(&tmp, &mask1, &mask2);
+ * for_each_cpu(cpu, &tmp)
+ * ...
+ *
+ * After the loop, cpu is >= nr_cpu_ids.
+ */
+#define for_each_cpu_andnot(cpu, mask1, mask2) \
+ for_each_andnot_bit(cpu, cpumask_bits(mask1), cpumask_bits(mask2), nr_cpumask_bits)
+
/**
* cpumask_any_but - return a "random" in a cpumask, but not this one.
* @mask: the cpumask to search
diff --git a/include/linux/find.h b/include/linux/find.h
index 2235af19e7e1..ccaf61a0f5fd 100644
--- a/include/linux/find.h
+++ b/include/linux/find.h
@@ -498,6 +498,11 @@ unsigned long find_next_bit_le(const void *addr, unsigned
(bit) = find_next_and_bit((addr1), (addr2), (size), (bit)), (bit) < (size);\
(bit)++)
+#define for_each_andnot_bit(bit, addr1, addr2, size) \
+ for ((bit) = 0; \
+ (bit) = find_next_andnot_bit((addr1), (addr2), (size), (bit)), (bit) < (size);\
+ (bit)++)
+
/* same as for_each_set_bit() but use bit as value to start with */
#define for_each_set_bit_from(bit, addr, size) \
for (; (bit) = find_next_bit((addr), (size), (bit)), (bit) < (size); (bit)++)
--
2.31.1
Powered by blists - more mailing lists