lib/proportions: Remove unused code
By accident I stumbled across code that is no longer used. According to git grep, the global functions in lib/proportions.c are not used anywhere. This patch removes the old, unused code. Peter Zijlstra further commented: "Ah indeed, that got replaced with the flex proportion code a while back." Signed-off-by: Richard Cochran <rcochran@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/4265b49bed713fbe3faaf8c05da0e1792f09c0b3.1459432020.git.rcochran@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Richard Cochran
Ingo Molnar
Родитель
1e6d88ccf4
Коммит
d18d12d0ff
|
|
@ -1,137 +0,0 @@
|
|||
/*
|
||||
* FLoating proportions
|
||||
*
|
||||
* Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra
|
||||
*
|
||||
* This file contains the public data structure and API definitions.
|
||||
*/
|
||||
|
||||
#ifndef _LINUX_PROPORTIONS_H
|
||||
#define _LINUX_PROPORTIONS_H
|
||||
|
||||
#include <linux/percpu_counter.h>
|
||||
#include <linux/spinlock.h>
|
||||
#include <linux/mutex.h>
|
||||
#include <linux/gfp.h>
|
||||
|
||||
struct prop_global {
|
||||
/*
|
||||
* The period over which we differentiate
|
||||
*
|
||||
* period = 2^shift
|
||||
*/
|
||||
int shift;
|
||||
/*
|
||||
* The total event counter aka 'time'.
|
||||
*
|
||||
* Treated as an unsigned long; the lower 'shift - 1' bits are the
|
||||
* counter bits, the remaining upper bits the period counter.
|
||||
*/
|
||||
struct percpu_counter events;
|
||||
};
|
||||
|
||||
/*
|
||||
* global proportion descriptor
|
||||
*
|
||||
* this is needed to consistently flip prop_global structures.
|
||||
*/
|
||||
struct prop_descriptor {
|
||||
int index;
|
||||
struct prop_global pg[2];
|
||||
struct mutex mutex; /* serialize the prop_global switch */
|
||||
};
|
||||
|
||||
int prop_descriptor_init(struct prop_descriptor *pd, int shift, gfp_t gfp);
|
||||
void prop_change_shift(struct prop_descriptor *pd, int new_shift);
|
||||
|
||||
/*
|
||||
* ----- PERCPU ------
|
||||
*/
|
||||
|
||||
struct prop_local_percpu {
|
||||
/*
|
||||
* the local events counter
|
||||
*/
|
||||
struct percpu_counter events;
|
||||
|
||||
/*
|
||||
* snapshot of the last seen global state
|
||||
*/
|
||||
int shift;
|
||||
unsigned long period;
|
||||
raw_spinlock_t lock; /* protect the snapshot state */
|
||||
};
|
||||
|
||||
int prop_local_init_percpu(struct prop_local_percpu *pl, gfp_t gfp);
|
||||
void prop_local_destroy_percpu(struct prop_local_percpu *pl);
|
||||
void __prop_inc_percpu(struct prop_descriptor *pd, struct prop_local_percpu *pl);
|
||||
void prop_fraction_percpu(struct prop_descriptor *pd, struct prop_local_percpu *pl,
|
||||
long *numerator, long *denominator);
|
||||
|
||||
static inline
|
||||
void prop_inc_percpu(struct prop_descriptor *pd, struct prop_local_percpu *pl)
|
||||
{
|
||||
unsigned long flags;
|
||||
|
||||
local_irq_save(flags);
|
||||
__prop_inc_percpu(pd, pl);
|
||||
local_irq_restore(flags);
|
||||
}
|
||||
|
||||
/*
|
||||
* Limit the time part in order to ensure there are some bits left for the
|
||||
* cycle counter and fraction multiply.
|
||||
*/
|
||||
#if BITS_PER_LONG == 32
|
||||
#define PROP_MAX_SHIFT (3*BITS_PER_LONG/4)
|
||||
#else
|
||||
#define PROP_MAX_SHIFT (BITS_PER_LONG/2)
|
||||
#endif
|
||||
|
||||
#define PROP_FRAC_SHIFT (BITS_PER_LONG - PROP_MAX_SHIFT - 1)
|
||||
#define PROP_FRAC_BASE (1UL << PROP_FRAC_SHIFT)
|
||||
|
||||
void __prop_inc_percpu_max(struct prop_descriptor *pd,
|
||||
struct prop_local_percpu *pl, long frac);
|
||||
|
||||
|
||||
/*
|
||||
* ----- SINGLE ------
|
||||
*/
|
||||
|
||||
struct prop_local_single {
|
||||
/*
|
||||
* the local events counter
|
||||
*/
|
||||
unsigned long events;
|
||||
|
||||
/*
|
||||
* snapshot of the last seen global state
|
||||
* and a lock protecting this state
|
||||
*/
|
||||
unsigned long period;
|
||||
int shift;
|
||||
raw_spinlock_t lock; /* protect the snapshot state */
|
||||
};
|
||||
|
||||
#define INIT_PROP_LOCAL_SINGLE(name) \
|
||||
{ .lock = __RAW_SPIN_LOCK_UNLOCKED(name.lock), \
|
||||
}
|
||||
|
||||
int prop_local_init_single(struct prop_local_single *pl);
|
||||
void prop_local_destroy_single(struct prop_local_single *pl);
|
||||
void __prop_inc_single(struct prop_descriptor *pd, struct prop_local_single *pl);
|
||||
void prop_fraction_single(struct prop_descriptor *pd, struct prop_local_single *pl,
|
||||
long *numerator, long *denominator);
|
||||
|
||||
static inline
|
||||
void prop_inc_single(struct prop_descriptor *pd, struct prop_local_single *pl)
|
||||
{
|
||||
unsigned long flags;
|
||||
|
||||
local_irq_save(flags);
|
||||
__prop_inc_single(pd, pl);
|
||||
local_irq_restore(flags);
|
||||
}
|
||||
|
||||
#endif /* _LINUX_PROPORTIONS_H */
|
||||
|
|
@ -40,7 +40,6 @@ struct sched_param {
|
|||
#include <linux/pid.h>
|
||||
#include <linux/percpu.h>
|
||||
#include <linux/topology.h>
|
||||
#include <linux/proportions.h>
|
||||
#include <linux/seccomp.h>
|
||||
#include <linux/rcupdate.h>
|
||||
#include <linux/rculist.h>
|
||||
|
|
|
|||
|
|
@ -23,7 +23,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \
|
|||
rbtree.o radix-tree.o dump_stack.o timerqueue.o\
|
||||
idr.o int_sqrt.o extable.o \
|
||||
sha1.o md5.o irq_regs.o argv_split.o \
|
||||
proportions.o flex_proportions.o ratelimit.o show_mem.o \
|
||||
flex_proportions.o ratelimit.o show_mem.o \
|
||||
is_single_threaded.o plist.o decompress.o kobject_uevent.o \
|
||||
earlycpio.o seq_buf.o nmi_backtrace.o
|
||||
|
||||
|
|
|
|||
|
|
@ -1,407 +0,0 @@
|
|||
/*
|
||||
* Floating proportions
|
||||
*
|
||||
* Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra
|
||||
*
|
||||
* Description:
|
||||
*
|
||||
* The floating proportion is a time derivative with an exponentially decaying
|
||||
* history:
|
||||
*
|
||||
* p_{j} = \Sum_{i=0} (dx_{j}/dt_{-i}) / 2^(1+i)
|
||||
*
|
||||
* Where j is an element from {prop_local}, x_{j} is j's number of events,
|
||||
* and i the time period over which the differential is taken. So d/dt_{-i} is
|
||||
* the differential over the i-th last period.
|
||||
*
|
||||
* The decaying history gives smooth transitions. The time differential carries
|
||||
* the notion of speed.
|
||||
*
|
||||
* The denominator is 2^(1+i) because we want the series to be normalised, ie.
|
||||
*
|
||||
* \Sum_{i=0} 1/2^(1+i) = 1
|
||||
*
|
||||
* Further more, if we measure time (t) in the same events as x; so that:
|
||||
*
|
||||
* t = \Sum_{j} x_{j}
|
||||
*
|
||||
* we get that:
|
||||
*
|
||||
* \Sum_{j} p_{j} = 1
|
||||
*
|
||||
* Writing this in an iterative fashion we get (dropping the 'd's):
|
||||
*
|
||||
* if (++x_{j}, ++t > period)
|
||||
* t /= 2;
|
||||
* for_each (j)
|
||||
* x_{j} /= 2;
|
||||
*
|
||||
* so that:
|
||||
*
|
||||
* p_{j} = x_{j} / t;
|
||||
*
|
||||
* We optimize away the '/= 2' for the global time delta by noting that:
|
||||
*
|
||||
* if (++t > period) t /= 2:
|
||||
*
|
||||
* Can be approximated by:
|
||||
*
|
||||
* period/2 + (++t % period/2)
|
||||
*
|
||||
* [ Furthermore, when we choose period to be 2^n it can be written in terms of
|
||||
* binary operations and wraparound artefacts disappear. ]
|
||||
*
|
||||
* Also note that this yields a natural counter of the elapsed periods:
|
||||
*
|
||||
* c = t / (period/2)
|
||||
*
|
||||
* [ Its monotonic increasing property can be applied to mitigate the wrap-
|
||||
* around issue. ]
|
||||
*
|
||||
* This allows us to do away with the loop over all prop_locals on each period
|
||||
* expiration. By remembering the period count under which it was last accessed
|
||||
* as c_{j}, we can obtain the number of 'missed' cycles from:
|
||||
*
|
||||
* c - c_{j}
|
||||
*
|
||||
* We can then lazily catch up to the global period count every time we are
|
||||
* going to use x_{j}, by doing:
|
||||
*
|
||||
* x_{j} /= 2^(c - c_{j}), c_{j} = c
|
||||
*/
|
||||
|
||||
#include <linux/proportions.h>
|
||||
#include <linux/rcupdate.h>
|
||||
|
||||
int prop_descriptor_init(struct prop_descriptor *pd, int shift, gfp_t gfp)
|
||||
{
|
||||
int err;
|
||||
|
||||
if (shift > PROP_MAX_SHIFT)
|
||||
shift = PROP_MAX_SHIFT;
|
||||
|
||||
pd->index = 0;
|
||||
pd->pg[0].shift = shift;
|
||||
mutex_init(&pd->mutex);
|
||||
err = percpu_counter_init(&pd->pg[0].events, 0, gfp);
|
||||
if (err)
|
||||
goto out;
|
||||
|
||||
err = percpu_counter_init(&pd->pg[1].events, 0, gfp);
|
||||
if (err)
|
||||
percpu_counter_destroy(&pd->pg[0].events);
|
||||
|
||||
out:
|
||||
return err;
|
||||
}
|
||||
|
||||
/*
|
||||
* We have two copies, and flip between them to make it seem like an atomic
|
||||
* update. The update is not really atomic wrt the events counter, but
|
||||
* it is internally consistent with the bit layout depending on shift.
|
||||
*
|
||||
* We copy the events count, move the bits around and flip the index.
|
||||
*/
|
||||
void prop_change_shift(struct prop_descriptor *pd, int shift)
|
||||
{
|
||||
int index;
|
||||
int offset;
|
||||
u64 events;
|
||||
unsigned long flags;
|
||||
|
||||
if (shift > PROP_MAX_SHIFT)
|
||||
shift = PROP_MAX_SHIFT;
|
||||
|
||||
mutex_lock(&pd->mutex);
|
||||
|
||||
index = pd->index ^ 1;
|
||||
offset = pd->pg[pd->index].shift - shift;
|
||||
if (!offset)
|
||||
goto out;
|
||||
|
||||
pd->pg[index].shift = shift;
|
||||
|
||||
local_irq_save(flags);
|
||||
events = percpu_counter_sum(&pd->pg[pd->index].events);
|
||||
if (offset < 0)
|
||||
events <<= -offset;
|
||||
else
|
||||
events >>= offset;
|
||||
percpu_counter_set(&pd->pg[index].events, events);
|
||||
|
||||
/*
|
||||
* ensure the new pg is fully written before the switch
|
||||
*/
|
||||
smp_wmb();
|
||||
pd->index = index;
|
||||
local_irq_restore(flags);
|
||||
|
||||
synchronize_rcu();
|
||||
|
||||
out:
|
||||
mutex_unlock(&pd->mutex);
|
||||
}
|
||||
|
||||
/*
|
||||
* wrap the access to the data in an rcu_read_lock() section;
|
||||
* this is used to track the active references.
|
||||
*/
|
||||
static struct prop_global *prop_get_global(struct prop_descriptor *pd)
|
||||
__acquires(RCU)
|
||||
{
|
||||
int index;
|
||||
|
||||
rcu_read_lock();
|
||||
index = pd->index;
|
||||
/*
|
||||
* match the wmb from vcd_flip()
|
||||
*/
|
||||
smp_rmb();
|
||||
return &pd->pg[index];
|
||||
}
|
||||
|
||||
static void prop_put_global(struct prop_descriptor *pd, struct prop_global *pg)
|
||||
__releases(RCU)
|
||||
{
|
||||
rcu_read_unlock();
|
||||
}
|
||||
|
||||
static void
|
||||
prop_adjust_shift(int *pl_shift, unsigned long *pl_period, int new_shift)
|
||||
{
|
||||
int offset = *pl_shift - new_shift;
|
||||
|
||||
if (!offset)
|
||||
return;
|
||||
|
||||
if (offset < 0)
|
||||
*pl_period <<= -offset;
|
||||
else
|
||||
*pl_period >>= offset;
|
||||
|
||||
*pl_shift = new_shift;
|
||||
}
|
||||
|
||||
/*
|
||||
* PERCPU
|
||||
*/
|
||||
|
||||
#define PROP_BATCH (8*(1+ilog2(nr_cpu_ids)))
|
||||
|
||||
int prop_local_init_percpu(struct prop_local_percpu *pl, gfp_t gfp)
|
||||
{
|
||||
raw_spin_lock_init(&pl->lock);
|
||||
pl->shift = 0;
|
||||
pl->period = 0;
|
||||
return percpu_counter_init(&pl->events, 0, gfp);
|
||||
}
|
||||
|
||||
void prop_local_destroy_percpu(struct prop_local_percpu *pl)
|
||||
{
|
||||
percpu_counter_destroy(&pl->events);
|
||||
}
|
||||
|
||||
/*
|
||||
* Catch up with missed period expirations.
|
||||
*
|
||||
* until (c_{j} == c)
|
||||
* x_{j} -= x_{j}/2;
|
||||
* c_{j}++;
|
||||
*/
|
||||
static
|
||||
void prop_norm_percpu(struct prop_global *pg, struct prop_local_percpu *pl)
|
||||
{
|
||||
unsigned long period = 1UL << (pg->shift - 1);
|
||||
unsigned long period_mask = ~(period - 1);
|
||||
unsigned long global_period;
|
||||
unsigned long flags;
|
||||
|
||||
global_period = percpu_counter_read(&pg->events);
|
||||
global_period &= period_mask;
|
||||
|
||||
/*
|
||||
* Fast path - check if the local and global period count still match
|
||||
* outside of the lock.
|
||||
*/
|
||||
if (pl->period == global_period)
|
||||
return;
|
||||
|
||||
raw_spin_lock_irqsave(&pl->lock, flags);
|
||||
prop_adjust_shift(&pl->shift, &pl->period, pg->shift);
|
||||
|
||||
/*
|
||||
* For each missed period, we half the local counter.
|
||||
* basically:
|
||||
* pl->events >> (global_period - pl->period);
|
||||
*/
|
||||
period = (global_period - pl->period) >> (pg->shift - 1);
|
||||
if (period < BITS_PER_LONG) {
|
||||
s64 val = percpu_counter_read(&pl->events);
|
||||
|
||||
if (val < (nr_cpu_ids * PROP_BATCH))
|
||||
val = percpu_counter_sum(&pl->events);
|
||||
|
||||
__percpu_counter_add(&pl->events, -val + (val >> period),
|
||||
PROP_BATCH);
|
||||
} else
|
||||
percpu_counter_set(&pl->events, 0);
|
||||
|
||||
pl->period = global_period;
|
||||
raw_spin_unlock_irqrestore(&pl->lock, flags);
|
||||
}
|
||||
|
||||
/*
|
||||
* ++x_{j}, ++t
|
||||
*/
|
||||
void __prop_inc_percpu(struct prop_descriptor *pd, struct prop_local_percpu *pl)
|
||||
{
|
||||
struct prop_global *pg = prop_get_global(pd);
|
||||
|
||||
prop_norm_percpu(pg, pl);
|
||||
__percpu_counter_add(&pl->events, 1, PROP_BATCH);
|
||||
percpu_counter_add(&pg->events, 1);
|
||||
prop_put_global(pd, pg);
|
||||
}
|
||||
|
||||
/*
|
||||
* identical to __prop_inc_percpu, except that it limits this pl's fraction to
|
||||
* @frac/PROP_FRAC_BASE by ignoring events when this limit has been exceeded.
|
||||
*/
|
||||
void __prop_inc_percpu_max(struct prop_descriptor *pd,
|
||||
struct prop_local_percpu *pl, long frac)
|
||||
{
|
||||
struct prop_global *pg = prop_get_global(pd);
|
||||
|
||||
prop_norm_percpu(pg, pl);
|
||||
|
||||
if (unlikely(frac != PROP_FRAC_BASE)) {
|
||||
unsigned long period_2 = 1UL << (pg->shift - 1);
|
||||
unsigned long counter_mask = period_2 - 1;
|
||||
unsigned long global_count;
|
||||
long numerator, denominator;
|
||||
|
||||
numerator = percpu_counter_read_positive(&pl->events);
|
||||
global_count = percpu_counter_read(&pg->events);
|
||||
denominator = period_2 + (global_count & counter_mask);
|
||||
|
||||
if (numerator > ((denominator * frac) >> PROP_FRAC_SHIFT))
|
||||
goto out_put;
|
||||
}
|
||||
|
||||
percpu_counter_add(&pl->events, 1);
|
||||
percpu_counter_add(&pg->events, 1);
|
||||
|
||||
out_put:
|
||||
prop_put_global(pd, pg);
|
||||
}
|
||||
|
||||
/*
|
||||
* Obtain a fraction of this proportion
|
||||
*
|
||||
* p_{j} = x_{j} / (period/2 + t % period/2)
|
||||
*/
|
||||
void prop_fraction_percpu(struct prop_descriptor *pd,
|
||||
struct prop_local_percpu *pl,
|
||||
long *numerator, long *denominator)
|
||||
{
|
||||
struct prop_global *pg = prop_get_global(pd);
|
||||
unsigned long period_2 = 1UL << (pg->shift - 1);
|
||||
unsigned long counter_mask = period_2 - 1;
|
||||
unsigned long global_count;
|
||||
|
||||
prop_norm_percpu(pg, pl);
|
||||
*numerator = percpu_counter_read_positive(&pl->events);
|
||||
|
||||
global_count = percpu_counter_read(&pg->events);
|
||||
*denominator = period_2 + (global_count & counter_mask);
|
||||
|
||||
prop_put_global(pd, pg);
|
||||
}
|
||||
|
||||
/*
|
||||
* SINGLE
|
||||
*/
|
||||
|
||||
int prop_local_init_single(struct prop_local_single *pl)
|
||||
{
|
||||
raw_spin_lock_init(&pl->lock);
|
||||
pl->shift = 0;
|
||||
pl->period = 0;
|
||||
pl->events = 0;
|
||||
return 0;
|
||||
}
|
||||
|
||||
void prop_local_destroy_single(struct prop_local_single *pl)
|
||||
{
|
||||
}
|
||||
|
||||
/*
|
||||
* Catch up with missed period expirations.
|
||||
*/
|
||||
static
|
||||
void prop_norm_single(struct prop_global *pg, struct prop_local_single *pl)
|
||||
{
|
||||
unsigned long period = 1UL << (pg->shift - 1);
|
||||
unsigned long period_mask = ~(period - 1);
|
||||
unsigned long global_period;
|
||||
unsigned long flags;
|
||||
|
||||
global_period = percpu_counter_read(&pg->events);
|
||||
global_period &= period_mask;
|
||||
|
||||
/*
|
||||
* Fast path - check if the local and global period count still match
|
||||
* outside of the lock.
|
||||
*/
|
||||
if (pl->period == global_period)
|
||||
return;
|
||||
|
||||
raw_spin_lock_irqsave(&pl->lock, flags);
|
||||
prop_adjust_shift(&pl->shift, &pl->period, pg->shift);
|
||||
/*
|
||||
* For each missed period, we half the local counter.
|
||||
*/
|
||||
period = (global_period - pl->period) >> (pg->shift - 1);
|
||||
if (likely(period < BITS_PER_LONG))
|
||||
pl->events >>= period;
|
||||
else
|
||||
pl->events = 0;
|
||||
pl->period = global_period;
|
||||
raw_spin_unlock_irqrestore(&pl->lock, flags);
|
||||
}
|
||||
|
||||
/*
|
||||
* ++x_{j}, ++t
|
||||
*/
|
||||
void __prop_inc_single(struct prop_descriptor *pd, struct prop_local_single *pl)
|
||||
{
|
||||
struct prop_global *pg = prop_get_global(pd);
|
||||
|
||||
prop_norm_single(pg, pl);
|
||||
pl->events++;
|
||||
percpu_counter_add(&pg->events, 1);
|
||||
prop_put_global(pd, pg);
|
||||
}
|
||||
|
||||
/*
|
||||
* Obtain a fraction of this proportion
|
||||
*
|
||||
* p_{j} = x_{j} / (period/2 + t % period/2)
|
||||
*/
|
||||
void prop_fraction_single(struct prop_descriptor *pd,
|
||||
struct prop_local_single *pl,
|
||||
long *numerator, long *denominator)
|
||||
{
|
||||
struct prop_global *pg = prop_get_global(pd);
|
||||
unsigned long period_2 = 1UL << (pg->shift - 1);
|
||||
unsigned long counter_mask = period_2 - 1;
|
||||
unsigned long global_count;
|
||||
|
||||
prop_norm_single(pg, pl);
|
||||
*numerator = pl->events;
|
||||
|
||||
global_count = percpu_counter_read(&pg->events);
|
||||
*denominator = period_2 + (global_count & counter_mask);
|
||||
|
||||
prop_put_global(pd, pg);
|
||||
}
|
||||
Загрузка…
Ссылка в новой задаче