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.
Cc: Ingo Molnar <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Signed-off-by: Richard Cochran <[email protected]>
---
include/linux/proportions.h | 137 ---------------
include/linux/sched.h | 1 -
lib/Makefile | 2 +-
lib/proportions.c | 407 --------------------------------------------
4 files changed, 1 insertion(+), 546 deletions(-)
delete mode 100644 include/linux/proportions.h
delete mode 100644 lib/proportions.c
diff --git a/include/linux/proportions.h b/include/linux/proportions.h
deleted file mode 100644
index 2122133..0000000
--- a/include/linux/proportions.h
+++ /dev/null
@@ -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 */
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 60bba7e..6dd25d1 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.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>
diff --git a/lib/Makefile b/lib/Makefile
index 7bd6fd4..a65e9a8 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -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
diff --git a/lib/proportions.c b/lib/proportions.c
deleted file mode 100644
index efa54f25..0000000
--- a/lib/proportions.c
+++ /dev/null
@@ -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);
-}
--
2.1.4
By accident I stumbled across code that has never been used. This
driver has EXPORT_SYMBOL functions, and the only user of the code is
pcrypt.c, but this only uses a subset of the exported symbols.
According to 'git log -G', the functions, padata_set_cpumasks,
padata_add_cpu, and padata_remove_cpu have never been used since they
were first introduced. This patch removes the unused code.
On one 64 bit build, with CRYPTO_PCRYPT built in, the text is more
than 4k smaller.
kbuild_hp> size $KBUILD_OUTPUT/vmlinux
text data bss dec hex filename
10566658 4678360 1122304 16367322 f9beda vmlinux
10561984 4678360 1122304 16362648 f9ac98 vmlinux
On another config, 32 bit, the saving is about 0.5k bytes.
kbuild_hp-x86> size $KBUILD_OUTPUT/vmlinux
6012005 2409513 2785280 11206798 ab008e vmlinux
6011491 2409513 2785280 11206284 aafe8c vmlinux
Cc: Steffen Klassert <[email protected]>
Cc: [email protected]
Signed-off-by: Richard Cochran <[email protected]>
---
include/linux/padata.h | 5 ---
kernel/padata.c | 99 --------------------------------------------------
2 files changed, 104 deletions(-)
diff --git a/include/linux/padata.h b/include/linux/padata.h
index 4386946..113ee62 100644
--- a/include/linux/padata.h
+++ b/include/linux/padata.h
@@ -175,11 +175,6 @@ extern int padata_do_parallel(struct padata_instance *pinst,
extern void padata_do_serial(struct padata_priv *padata);
extern int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
cpumask_var_t cpumask);
-extern int padata_set_cpumasks(struct padata_instance *pinst,
- cpumask_var_t pcpumask,
- cpumask_var_t cbcpumask);
-extern int padata_add_cpu(struct padata_instance *pinst, int cpu, int mask);
-extern int padata_remove_cpu(struct padata_instance *pinst, int cpu, int mask);
extern int padata_start(struct padata_instance *pinst);
extern void padata_stop(struct padata_instance *pinst);
extern int padata_register_cpumask_notifier(struct padata_instance *pinst,
diff --git a/kernel/padata.c b/kernel/padata.c
index b38bea9..7436dd6 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -607,33 +607,6 @@ out_replace:
}
/**
- * padata_set_cpumasks - Set both parallel and serial cpumasks. The first
- * one is used by parallel workers and the second one
- * by the wokers doing serialization.
- *
- * @pinst: padata instance
- * @pcpumask: the cpumask to use for parallel workers
- * @cbcpumask: the cpumsak to use for serial workers
- */
-int padata_set_cpumasks(struct padata_instance *pinst, cpumask_var_t pcpumask,
- cpumask_var_t cbcpumask)
-{
- int err;
-
- mutex_lock(&pinst->lock);
- get_online_cpus();
-
- err = __padata_set_cpumasks(pinst, pcpumask, cbcpumask);
-
- put_online_cpus();
- mutex_unlock(&pinst->lock);
-
- return err;
-
-}
-EXPORT_SYMBOL(padata_set_cpumasks);
-
-/**
* padata_set_cpumask: Sets specified by @cpumask_type cpumask to the value
* equivalent to @cpumask.
*
@@ -694,42 +667,6 @@ static int __padata_add_cpu(struct padata_instance *pinst, int cpu)
return 0;
}
- /**
- * padata_add_cpu - add a cpu to one or both(parallel and serial)
- * padata cpumasks.
- *
- * @pinst: padata instance
- * @cpu: cpu to add
- * @mask: bitmask of flags specifying to which cpumask @cpu shuld be added.
- * The @mask may be any combination of the following flags:
- * PADATA_CPU_SERIAL - serial cpumask
- * PADATA_CPU_PARALLEL - parallel cpumask
- */
-
-int padata_add_cpu(struct padata_instance *pinst, int cpu, int mask)
-{
- int err;
-
- if (!(mask & (PADATA_CPU_SERIAL | PADATA_CPU_PARALLEL)))
- return -EINVAL;
-
- mutex_lock(&pinst->lock);
-
- get_online_cpus();
- if (mask & PADATA_CPU_SERIAL)
- cpumask_set_cpu(cpu, pinst->cpumask.cbcpu);
- if (mask & PADATA_CPU_PARALLEL)
- cpumask_set_cpu(cpu, pinst->cpumask.pcpu);
-
- err = __padata_add_cpu(pinst, cpu);
- put_online_cpus();
-
- mutex_unlock(&pinst->lock);
-
- return err;
-}
-EXPORT_SYMBOL(padata_add_cpu);
-
static int __padata_remove_cpu(struct padata_instance *pinst, int cpu)
{
struct parallel_data *pd = NULL;
@@ -754,41 +691,6 @@ static int __padata_remove_cpu(struct padata_instance *pinst, int cpu)
return 0;
}
- /**
- * padata_remove_cpu - remove a cpu from the one or both(serial and parallel)
- * padata cpumasks.
- *
- * @pinst: padata instance
- * @cpu: cpu to remove
- * @mask: bitmask specifying from which cpumask @cpu should be removed
- * The @mask may be any combination of the following flags:
- * PADATA_CPU_SERIAL - serial cpumask
- * PADATA_CPU_PARALLEL - parallel cpumask
- */
-int padata_remove_cpu(struct padata_instance *pinst, int cpu, int mask)
-{
- int err;
-
- if (!(mask & (PADATA_CPU_SERIAL | PADATA_CPU_PARALLEL)))
- return -EINVAL;
-
- mutex_lock(&pinst->lock);
-
- get_online_cpus();
- if (mask & PADATA_CPU_SERIAL)
- cpumask_clear_cpu(cpu, pinst->cpumask.cbcpu);
- if (mask & PADATA_CPU_PARALLEL)
- cpumask_clear_cpu(cpu, pinst->cpumask.pcpu);
-
- err = __padata_remove_cpu(pinst, cpu);
- put_online_cpus();
-
- mutex_unlock(&pinst->lock);
-
- return err;
-}
-EXPORT_SYMBOL(padata_remove_cpu);
-
/**
* padata_start - start the parallel processing
*
@@ -1091,7 +993,6 @@ err_free_inst:
err:
return NULL;
}
-EXPORT_SYMBOL(padata_alloc);
/**
* padata_free - free a padata instance
--
2.1.4
On Thu, Mar 31, 2016 at 03:51:32PM +0200, Richard Cochran wrote:
> 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.
Ah indeed, that got replaced with the flex proportion code a while back.
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Commit-ID: d18d12d0ff07c47fb913f297c174f30a3f96042d
Gitweb: http://git.kernel.org/tip/d18d12d0ff07c47fb913f297c174f30a3f96042d
Author: Richard Cochran <[email protected]>
AuthorDate: Thu, 31 Mar 2016 15:51:32 +0200
Committer: Ingo Molnar <[email protected]>
CommitDate: Fri, 1 Apr 2016 08:53:49 +0200
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 <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: http://lkml.kernel.org/r/4265b49bed713fbe3faaf8c05da0e1792f09c0b3.1459432020.git.rcochran@linutronix.de
Signed-off-by: Ingo Molnar <[email protected]>
---
include/linux/proportions.h | 137 ---------------
include/linux/sched.h | 1 -
lib/Makefile | 2 +-
lib/proportions.c | 407 --------------------------------------------
4 files changed, 1 insertion(+), 546 deletions(-)
diff --git a/include/linux/proportions.h b/include/linux/proportions.h
deleted file mode 100644
index 2122133..0000000
--- a/include/linux/proportions.h
+++ /dev/null
@@ -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 */
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 60bba7e..6dd25d1 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.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>
diff --git a/lib/Makefile b/lib/Makefile
index 7bd6fd4..a65e9a8 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -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
diff --git a/lib/proportions.c b/lib/proportions.c
deleted file mode 100644
index efa54f25..0000000
--- a/lib/proportions.c
+++ /dev/null
@@ -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);
-}