linux_dsm_epyc7002/drivers/md/bcache/stats.c

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 21:07:57 +07:00
// SPDX-License-Identifier: GPL-2.0
/*
* bcache stats code
*
* Copyright 2012 Google, Inc.
*/
#include "bcache.h"
#include "stats.h"
#include "btree.h"
#include "sysfs.h"
/*
* We keep absolute totals of various statistics, and addionally a set of three
* rolling averages.
*
* Every so often, a timer goes off and rescales the rolling averages.
* accounting_rescale[] is how many times the timer has to go off before we
* rescale each set of numbers; that gets us half lives of 5 minutes, one hour,
* and one day.
*
* accounting_delay is how often the timer goes off - 22 times in 5 minutes,
* and accounting_weight is what we use to rescale:
*
* pow(31 / 32, 22) ~= 1/2
*
* So that we don't have to increment each set of numbers every time we (say)
* get a cache hit, we increment a single atomic_t in acc->collector, and when
* the rescale function runs it resets the atomic counter to 0 and adds its
* old value to each of the exported numbers.
*
* To reduce rounding error, the numbers in struct cache_stats are all
* stored left shifted by 16, and scaled back in the sysfs show() function.
*/
static const unsigned DAY_RESCALE = 288;
static const unsigned HOUR_RESCALE = 12;
static const unsigned FIVE_MINUTE_RESCALE = 1;
static const unsigned accounting_delay = (HZ * 300) / 22;
static const unsigned accounting_weight = 32;
/* sysfs reading/writing */
read_attribute(cache_hits);
read_attribute(cache_misses);
read_attribute(cache_bypass_hits);
read_attribute(cache_bypass_misses);
read_attribute(cache_hit_ratio);
read_attribute(cache_readaheads);
read_attribute(cache_miss_collisions);
read_attribute(bypassed);
SHOW(bch_stats)
{
struct cache_stats *s =
container_of(kobj, struct cache_stats, kobj);
#define var(stat) (s->stat >> 16)
var_print(cache_hits);
var_print(cache_misses);
var_print(cache_bypass_hits);
var_print(cache_bypass_misses);
sysfs_print(cache_hit_ratio,
DIV_SAFE(var(cache_hits) * 100,
var(cache_hits) + var(cache_misses)));
var_print(cache_readaheads);
var_print(cache_miss_collisions);
sysfs_hprint(bypassed, var(sectors_bypassed) << 9);
#undef var
return 0;
}
STORE(bch_stats)
{
return size;
}
static void bch_stats_release(struct kobject *k)
{
}
static struct attribute *bch_stats_files[] = {
&sysfs_cache_hits,
&sysfs_cache_misses,
&sysfs_cache_bypass_hits,
&sysfs_cache_bypass_misses,
&sysfs_cache_hit_ratio,
&sysfs_cache_readaheads,
&sysfs_cache_miss_collisions,
&sysfs_bypassed,
NULL
};
static KTYPE(bch_stats);
int bch_cache_accounting_add_kobjs(struct cache_accounting *acc,
struct kobject *parent)
{
int ret = kobject_add(&acc->total.kobj, parent,
"stats_total");
ret = ret ?: kobject_add(&acc->five_minute.kobj, parent,
"stats_five_minute");
ret = ret ?: kobject_add(&acc->hour.kobj, parent,
"stats_hour");
ret = ret ?: kobject_add(&acc->day.kobj, parent,
"stats_day");
return ret;
}
void bch_cache_accounting_clear(struct cache_accounting *acc)
{
memset(&acc->total.cache_hits,
0,
sizeof(unsigned long) * 7);
}
void bch_cache_accounting_destroy(struct cache_accounting *acc)
{
kobject_put(&acc->total.kobj);
kobject_put(&acc->five_minute.kobj);
kobject_put(&acc->hour.kobj);
kobject_put(&acc->day.kobj);
atomic_set(&acc->closing, 1);
if (del_timer_sync(&acc->timer))
closure_return(&acc->cl);
}
/* EWMA scaling */
static void scale_stat(unsigned long *stat)
{
*stat = ewma_add(*stat, 0, accounting_weight, 0);
}
static void scale_stats(struct cache_stats *stats, unsigned long rescale_at)
{
if (++stats->rescale == rescale_at) {
stats->rescale = 0;
scale_stat(&stats->cache_hits);
scale_stat(&stats->cache_misses);
scale_stat(&stats->cache_bypass_hits);
scale_stat(&stats->cache_bypass_misses);
scale_stat(&stats->cache_readaheads);
scale_stat(&stats->cache_miss_collisions);
scale_stat(&stats->sectors_bypassed);
}
}
static void scale_accounting(struct timer_list *t)
{
struct cache_accounting *acc = from_timer(acc, t, timer);
#define move_stat(name) do { \
unsigned t = atomic_xchg(&acc->collector.name, 0); \
t <<= 16; \
acc->five_minute.name += t; \
acc->hour.name += t; \
acc->day.name += t; \
acc->total.name += t; \
} while (0)
move_stat(cache_hits);
move_stat(cache_misses);
move_stat(cache_bypass_hits);
move_stat(cache_bypass_misses);
move_stat(cache_readaheads);
move_stat(cache_miss_collisions);
move_stat(sectors_bypassed);
scale_stats(&acc->total, 0);
scale_stats(&acc->day, DAY_RESCALE);
scale_stats(&acc->hour, HOUR_RESCALE);
scale_stats(&acc->five_minute, FIVE_MINUTE_RESCALE);
acc->timer.expires += accounting_delay;
if (!atomic_read(&acc->closing))
add_timer(&acc->timer);
else
closure_return(&acc->cl);
}
static void mark_cache_stats(struct cache_stat_collector *stats,
bool hit, bool bypass)
{
if (!bypass)
if (hit)
atomic_inc(&stats->cache_hits);
else
atomic_inc(&stats->cache_misses);
else
if (hit)
atomic_inc(&stats->cache_bypass_hits);
else
atomic_inc(&stats->cache_bypass_misses);
}
void bch_mark_cache_accounting(struct cache_set *c, struct bcache_device *d,
bool hit, bool bypass)
{
struct cached_dev *dc = container_of(d, struct cached_dev, disk);
mark_cache_stats(&dc->accounting.collector, hit, bypass);
mark_cache_stats(&c->accounting.collector, hit, bypass);
}
void bch_mark_cache_readahead(struct cache_set *c, struct bcache_device *d)
{
struct cached_dev *dc = container_of(d, struct cached_dev, disk);
atomic_inc(&dc->accounting.collector.cache_readaheads);
atomic_inc(&c->accounting.collector.cache_readaheads);
}
void bch_mark_cache_miss_collision(struct cache_set *c, struct bcache_device *d)
{
struct cached_dev *dc = container_of(d, struct cached_dev, disk);
atomic_inc(&dc->accounting.collector.cache_miss_collisions);
atomic_inc(&c->accounting.collector.cache_miss_collisions);
}
void bch_mark_sectors_bypassed(struct cache_set *c, struct cached_dev *dc,
int sectors)
{
atomic_add(sectors, &dc->accounting.collector.sectors_bypassed);
atomic_add(sectors, &c->accounting.collector.sectors_bypassed);
}
void bch_cache_accounting_init(struct cache_accounting *acc,
struct closure *parent)
{
kobject_init(&acc->total.kobj, &bch_stats_ktype);
kobject_init(&acc->five_minute.kobj, &bch_stats_ktype);
kobject_init(&acc->hour.kobj, &bch_stats_ktype);
kobject_init(&acc->day.kobj, &bch_stats_ktype);
closure_init(&acc->cl, parent);
timer_setup(&acc->timer, scale_accounting, 0);
acc->timer.expires = jiffies + accounting_delay;
add_timer(&acc->timer);
}