auto_ckpt.c File Reference

Autonomic checkpoint interval selection module. More...

#include <mm/auto_ckpt.h>
#include <log/stats.h>
#include <lp/process.h>
#include <math.h>

Include dependency graph for auto_ckpt.c:

Macros
#define	EXP_AVG(f, old_v, sample)

Functions
void	auto_ckpt_init (void)
	Initialize the thread-local context for the auto checkpoint module.
void	auto_ckpt_on_gvt (void)
	Compute the thread-local metrics needed for the per-LP computations. More...
void	auto_ckpt_lp_init (struct auto_ckpt *auto_ckpt)
	Initialize the per-LP context for the auto checkpoint module. More...
void	auto_ckpt_recompute (struct auto_ckpt *auto_ckpt, uint_fast32_t state_size)
	Compute the optimal checkpoint interval of the current LP and set it. More...

Variables
struct {
double   ckpt_avg_cost
double   inv_sil_avg_cost
}	ackpt

Detailed Description

Autonomic checkpoint interval selection module.

The module which attempts to select the best checkpoint interval

Copyright

Copyright (C) 2008-2022 HPDCS Group https://hpdcs.github.io

Macro Definition Documentation

EXP_AVG

#define EXP_AVG	(		f,
			old_v,
			sample
	)

Value:

    __extension__({                                                                                                \
        double s = (sample);                                                                                   \
        double o = (old_v);                                                                                    \
        o *(((f)-1.0) / (f)) + s *(1.0 / (f));                                                                 \
    })

Compute a new value of the exponential moving average

Parameters

f	the retention factor for old observations
old_v	the latest value of the moving average
sample	the new value to include in the average

Returns

the new value of the exponential moving average

Function Documentation

auto_ckpt_lp_init()

void auto_ckpt_lp_init

(

struct auto_ckpt *

auto_ckpt

)

Initialize the per-LP context for the auto checkpoint module.

Parameters

auto_ckpt

a pointer to the LP auto checkpoint context to initialize

auto_ckpt_on_gvt()

void auto_ckpt_on_gvt

(

void

)

Compute the thread-local metrics needed for the per-LP computations.

This function should be called only at the end of GVT reductions, because the used statistics values are representative only in that moment.

auto_ckpt_recompute()

void auto_ckpt_recompute	(	struct auto_ckpt *	auto_ckpt,
		uint_fast32_t	state_size
	)

Compute the optimal checkpoint interval of the current LP and set it.

Parameters

auto_ckpt	a pointer to the auto checkpoint context of the current LP
state_size	the size in bytes of the checkpoint-able state of the current LP