Subject: [merged] softirq-use-ffs-in-__do_softirq.patch removed from -mm tree
To: joe@xxxxxxxxxxx,fweisbec@xxxxxxxxx,mingo@xxxxxxx,tglx@xxxxxxxxxxxxx,mm-commits@xxxxxxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Tue, 28 Jan 2014 11:09:49 -0800
The patch titled
Subject: softirq: use ffs() in __do_softirq()
has been removed from the -mm tree. Its filename was
softirq-use-ffs-in-__do_softirq.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Joe Perches <joe@xxxxxxxxxxx>
Subject: softirq: use ffs() in __do_softirq()
Possible speed improvement of __do_softirq() by using ffs() instead of
using a while loop with an & 1 test then single bit shift.
Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/softirq.c | 45 +++++++++++++++++++++++----------------------
1 file changed, 23 insertions(+), 22 deletions(-)
diff -puN kernel/softirq.c~softirq-use-ffs-in-__do_softirq kernel/softirq.c
--- a/kernel/softirq.c~softirq-use-ffs-in-__do_softirq
+++ a/kernel/softirq.c
@@ -229,6 +229,7 @@ asmlinkage void __do_softirq(void)
struct softirq_action *h;
bool in_hardirq;
__u32 pending;
+ int softirq_bit;
int cpu;
/*
@@ -253,30 +254,30 @@ restart:
h = softirq_vec;
- do {
- if (pending & 1) {
- unsigned int vec_nr = h - softirq_vec;
- int prev_count = preempt_count();
-
- kstat_incr_softirqs_this_cpu(vec_nr);
-
- trace_softirq_entry(vec_nr);
- h->action(h);
- trace_softirq_exit(vec_nr);
- if (unlikely(prev_count != preempt_count())) {
- printk(KERN_ERR "huh, entered softirq %u %s %p"
- "with preempt_count %08x,"
- " exited with %08x?\n", vec_nr,
- softirq_to_name[vec_nr], h->action,
- prev_count, preempt_count());
- preempt_count_set(prev_count);
- }
-
- rcu_bh_qs(cpu);
+ while ((softirq_bit = ffs(pending))) {
+ unsigned int vec_nr;
+ int prev_count;
+
+ h += softirq_bit - 1;
+
+ vec_nr = h - softirq_vec;
+ prev_count = preempt_count();
+
+ kstat_incr_softirqs_this_cpu(vec_nr);
+
+ trace_softirq_entry(vec_nr);
+ h->action(h);
+ trace_softirq_exit(vec_nr);
+ if (unlikely(prev_count != preempt_count())) {
+ printk(KERN_ERR "huh, entered softirq %u %s %p with preempt_count %08x, exited with %08x?\n",
+ vec_nr, softirq_to_name[vec_nr], h->action,
+ prev_count, preempt_count());
+ preempt_count_set(prev_count);
}
+ rcu_bh_qs(cpu);
h++;
- pending >>= 1;
- } while (pending);
+ pending >>= softirq_bit;
+ }
local_irq_disable();
_
Patches currently in -mm which might be from joe@xxxxxxxxxxx are
origin.patch
lib-genallocc-add-check-gen_pool_dma_alloc-if-dma-pointer-is-not-null.patch
linux-next.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
