From: Eric Sandeen <sandeen@redhat.com> Date: Mon, 4 Aug 2008 14:37:26 -0500 Subject: [fs] add percpu_counter_add & _sub Message-id: 48975A76.70704@redhat.com O-Subject: [PATCH RHEL5 4/9] UPDATED percpu_counter_add & _sub Bugzilla: 443896 RH-Acked-by: Jeff Layton <jlayton@redhat.com> RH-Acked-by: Alexander Viro <aviro@redhat.com> RH-Acked-by: Jeff Moyer <jmoyer@redhat.com> This is for: Bugzilla Bug 443896: RFE: [Ext4 enabler] backport vfs helpers to facilitate ext4 backport and testing Incorporates, roughly: From: Peter Zijlstra <a.p.zijlstra@chello.nl> Date: Wed, 17 Oct 2007 06:25:42 +0000 (-0700) Subject: lib: percpu_counter_add X-Git-Tag: v2.6.24-rc1~814 X-Git-Url: http://git.engineering.redhat.com/?p=linux-2.6.git;a=commitdiff_plain;h=aa0dff2d09bfa50b7d02714a45920c64568e699d lib: percpu_counter_add s/percpu_counter_mod/percpu_counter_add/ Because its a better name, _mod implies modulo. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> diff --git a/include/linux/percpu_counter.h b/include/linux/percpu_counter.h index f5aa593..d884622 100644 --- a/include/linux/percpu_counter.h +++ b/include/linux/percpu_counter.h @@ -39,6 +39,7 @@ static inline void percpu_counter_destroy(struct percpu_counter *fbc) } void percpu_counter_mod(struct percpu_counter *fbc, s32 amount); +void percpu_counter_mod64(struct percpu_counter *fbc, s64 amount); s64 percpu_counter_sum(struct percpu_counter *fbc); static inline s64 percpu_counter_read(struct percpu_counter *fbc) @@ -84,6 +85,14 @@ percpu_counter_mod(struct percpu_counter *fbc, s32 amount) preempt_enable(); } +static inline void +percpu_counter_mod64(struct percpu_counter *fbc, s64 amount) +{ + preempt_disable(); + fbc->count += amount; + preempt_enable(); +} + static inline s64 percpu_counter_read(struct percpu_counter *fbc) { return fbc->count; @@ -111,4 +120,14 @@ static inline void percpu_counter_dec(struct percpu_counter *fbc) percpu_counter_mod(fbc, -1); } +static inline void percpu_counter_add(struct percpu_counter *fbc, s64 amount) +{ + percpu_counter_mod64(fbc, amount); +} + +static inline void percpu_counter_sub(struct percpu_counter *fbc, s64 amount) +{ + percpu_counter_mod64(fbc, -amount); +} + #endif /* _LINUX_PERCPU_COUNTER_H */ diff --git a/lib/percpu_counter.c b/lib/percpu_counter.c index 8504490..3aa133b 100644 --- a/lib/percpu_counter.c +++ b/lib/percpu_counter.c @@ -25,6 +25,26 @@ void percpu_counter_mod(struct percpu_counter *fbc, s32 amount) } EXPORT_SYMBOL(percpu_counter_mod); +void percpu_counter_mod64(struct percpu_counter *fbc, s64 amount) +{ + s64 count; + s32 *pcount; + int cpu = get_cpu(); + + pcount = per_cpu_ptr(fbc->counters, cpu); + count = *pcount + amount; + if (count >= FBC_BATCH || count <= -FBC_BATCH) { + spin_lock(&fbc->lock); + fbc->count += count; + *pcount = 0; + spin_unlock(&fbc->lock); + } else { + *pcount = count; + } + put_cpu(); +} +EXPORT_SYMBOL(percpu_counter_mod64); + /* * Add up all the per-cpu counts, return the result. This is a more accurate * but much slower version of percpu_counter_read_positive()