Because percpu counters can accumulate their per-cpu sums over time outside of the control of the callers, we need this patch that updates the maximum values when that happens.
I am adding a mininum value as well for conistency, due to the signed nature of the percpu_counters. However, I am not sure this will be of general use, and might be yet another indication that we need to duplicate those structures... Signed-off-by: Glauber Costa <[email protected]> --- include/linux/percpu_counter.h | 2 ++ include/linux/res_counter.h | 6 +----- kernel/res_counter.c | 6 +++--- lib/percpu_counter.c | 4 ++++ 4 files changed, 10 insertions(+), 8 deletions(-) diff --git a/include/linux/percpu_counter.h b/include/linux/percpu_counter.h index 8310548..639d2d5 100644 --- a/include/linux/percpu_counter.h +++ b/include/linux/percpu_counter.h @@ -18,6 +18,8 @@ struct percpu_counter { raw_spinlock_t lock; s64 count; + s64 max; + s64 min; #ifdef CONFIG_HOTPLUG_CPU struct list_head list; /* All percpu_counters are on a list */ #endif diff --git a/include/linux/res_counter.h b/include/linux/res_counter.h index 8c1c20e..3527827 100644 --- a/include/linux/res_counter.h +++ b/include/linux/res_counter.h @@ -27,10 +27,6 @@ struct res_counter { */ struct percpu_counter usage_pcp; /* - * the maximal value of the usage from the counter creation - */ - unsigned long long max_usage; - /* * the limit that usage cannot exceed */ unsigned long long limit; @@ -178,7 +174,7 @@ static inline void res_counter_reset_max(struct res_counter *cnt) unsigned long flags; raw_spin_lock_irqsave(&cnt->usage_pcp.lock, flags); - cnt->max_usage = __percpu_counter_sum_locked(&cnt->usage_pcp); + cnt->usage_pcp.max = __percpu_counter_sum_locked(&cnt->usage_pcp); raw_spin_unlock_irqrestore(&cnt->usage_pcp.lock, flags); } diff --git a/kernel/res_counter.c b/kernel/res_counter.c index 8a99943..7b05208 100644 --- a/kernel/res_counter.c +++ b/kernel/res_counter.c @@ -61,8 +61,8 @@ int __res_counter_add(struct res_counter *c, long val, bool fail) c->usage_pcp.count += val; - if (usage > c->max_usage) - c->max_usage = usage; + if (usage > c->usage_pcp.max) + c->usage_pcp.max = usage; out: raw_spin_unlock(&c->usage_pcp.lock); @@ -164,7 +164,7 @@ res_counter_member(struct res_counter *counter, int member) { switch (member) { case RES_MAX_USAGE: - return &counter->max_usage; + return &counter->usage_pcp.max; case RES_LIMIT: return &counter->limit; case RES_FAILCNT: diff --git a/lib/percpu_counter.c b/lib/percpu_counter.c index 0b6a672..6dff70b 100644 --- a/lib/percpu_counter.c +++ b/lib/percpu_counter.c @@ -81,6 +81,10 @@ void __percpu_counter_add(struct percpu_counter *fbc, s64 amount, s32 batch) raw_spin_lock(&fbc->lock); fbc->count += count; __this_cpu_write(*fbc->counters, 0); + if (fbc->count > fbc->max) + fbc->max = fbc->count; + if (fbc->count < fbc->min) + fbc->min = fbc->count; raw_spin_unlock(&fbc->lock); } else { __this_cpu_write(*fbc->counters, count); -- 1.7.4.1 _______________________________________________ Devel mailing list [email protected] https://openvz.org/mailman/listinfo/devel
