Release 4.14 drivers/lightnvm/pblk-rl.c

Directory: drivers/lightnvm
/*
 * Copyright (C) 2016 CNEX Labs
 * Initial release: Javier Gonzalez <javier@cnexlabs.com>
 *                  Matias Bjorling <matias@cnexlabs.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * pblk-rl.c - pblk's rate limiter for user I/O
 *
 */

#include "pblk.h"



static void pblk_rl_kick_u_timer(struct pblk_rl *rl)
{
	mod_timer(&rl->u_timer, jiffies + msecs_to_jiffies(5000));
}

Contributors
Person Tokens Prop Commits CommitProp
Javier González 26 100.00% 1 100.00%
Total 26 100.00% 1 100.00%



int pblk_rl_is_limit(struct pblk_rl *rl)
{
	int rb_space;

	rb_space = atomic_read(&rl->rb_space);

	return (rb_space == 0);
}

Contributors
Person Tokens Prop Commits CommitProp
Javier González 30 100.00% 1 100.00%
Total 30 100.00% 1 100.00%



int pblk_rl_user_may_insert(struct pblk_rl *rl, int nr_entries)
{
	int rb_user_cnt = atomic_read(&rl->rb_user_cnt);
	int rb_space = atomic_read(&rl->rb_space);

	if (unlikely(rb_space >= 0) && (rb_space - nr_entries < 0))
		return NVM_IO_ERR;

	if (rb_user_cnt >= rl->rb_user_max)
		return NVM_IO_REQUEUE;

	return NVM_IO_OK;
}

Contributors
Person Tokens Prop Commits CommitProp
Javier González 69 100.00% 3 100.00%
Total 69 100.00% 3 100.00%



void pblk_rl_inserted(struct pblk_rl *rl, int nr_entries)
{
	int rb_space = atomic_read(&rl->rb_space);

	if (unlikely(rb_space >= 0))
		atomic_sub(nr_entries, &rl->rb_space);
}

Contributors
Person Tokens Prop Commits CommitProp
Javier González 43 100.00% 1 100.00%
Total 43 100.00% 1 100.00%



int pblk_rl_gc_may_insert(struct pblk_rl *rl, int nr_entries)
{
	int rb_gc_cnt = atomic_read(&rl->rb_gc_cnt);
	int rb_user_active;

	/* If there is no user I/O let GC take over space on the write buffer */
	rb_user_active = READ_ONCE(rl->rb_user_active);
	return (!(rb_gc_cnt >= rl->rb_gc_max && rb_user_active));
}

Contributors
Person Tokens Prop Commits CommitProp
Javier González 51 100.00% 2 100.00%
Total 51 100.00% 2 100.00%



void pblk_rl_user_in(struct pblk_rl *rl, int nr_entries)
{
	atomic_add(nr_entries, &rl->rb_user_cnt);

	/* Release user I/O state. Protect from GC */
	smp_store_release(&rl->rb_user_active, 1);
	pblk_rl_kick_u_timer(rl);
}

Contributors
Person Tokens Prop Commits CommitProp
Javier González 39 100.00% 1 100.00%
Total 39 100.00% 1 100.00%



void pblk_rl_gc_in(struct pblk_rl *rl, int nr_entries)
{
	atomic_add(nr_entries, &rl->rb_gc_cnt);
}

Contributors
Person Tokens Prop Commits CommitProp
Javier González 23 100.00% 1 100.00%
Total 23 100.00% 1 100.00%



void pblk_rl_out(struct pblk_rl *rl, int nr_user, int nr_gc)
{
	atomic_sub(nr_user, &rl->rb_user_cnt);
	atomic_sub(nr_gc, &rl->rb_gc_cnt);
}

Contributors
Person Tokens Prop Commits CommitProp
Javier González 36 100.00% 1 100.00%
Total 36 100.00% 1 100.00%



unsigned long pblk_rl_nr_free_blks(struct pblk_rl *rl)
{
	return atomic_read(&rl->free_blocks);
}

Contributors
Person Tokens Prop Commits CommitProp
Javier González 20 100.00% 1 100.00%
Total 20 100.00% 1 100.00%

/*
 * We check for (i) the number of free blocks in the current LUN and (ii) the
 * total number of free blocks in the pblk instance. This is to even out the
 * number of free blocks on each LUN when GC kicks in.
 *
 * Only the total number of free blocks is used to configure the rate limiter.
 */


static int pblk_rl_update_rates(struct pblk_rl *rl, unsigned long max)
{
	unsigned long free_blocks = pblk_rl_nr_free_blks(rl);

	if (free_blocks >= rl->high) {
		rl->rb_user_max = max;
		rl->rb_gc_max = 0;
		rl->rb_state = PBLK_RL_HIGH;
	} else if (free_blocks < rl->high) {
		int shift = rl->high_pw - rl->rb_windows_pw;
		int user_windows = free_blocks >> shift;
		int user_max = user_windows << PBLK_MAX_REQ_ADDRS_PW;

		rl->rb_user_max = user_max;
		rl->rb_gc_max = max - user_max;

		if (free_blocks <= rl->rsv_blocks) {
			rl->rb_user_max = 0;
			rl->rb_gc_max = max;
		}

		/* In the worst case, we will need to GC lines in the low list
                 * (high valid sector count). If there are lines to GC on high
                 * or mid lists, these will be prioritized
                 */
		rl->rb_state = PBLK_RL_LOW;
	}

	return rl->rb_state;
}

Contributors
Person Tokens Prop Commits CommitProp
Javier González 136 100.00% 2 100.00%
Total 136 100.00% 2 100.00%



void pblk_rl_free_lines_inc(struct pblk_rl *rl, struct pblk_line *line)
{
	struct pblk *pblk = container_of(rl, struct pblk, rl);
	int blk_in_line = atomic_read(&line->blk_in_line);
	int ret;

	atomic_add(blk_in_line, &rl->free_blocks);
	/* Rates will not change that often - no need to lock update */
	ret = pblk_rl_update_rates(rl, rl->rb_budget);

	if (ret == (PBLK_RL_MID | PBLK_RL_LOW))
		pblk_gc_should_start(pblk);
	else
		pblk_gc_should_stop(pblk);
}

Contributors
Person Tokens Prop Commits CommitProp
Javier González 87 100.00% 2 100.00%
Total 87 100.00% 2 100.00%



void pblk_rl_free_lines_dec(struct pblk_rl *rl, struct pblk_line *line)
{
	int blk_in_line = atomic_read(&line->blk_in_line);

	atomic_sub(blk_in_line, &rl->free_blocks);
}

Contributors
Person Tokens Prop Commits CommitProp
Javier González 36 100.00% 3 100.00%
Total 36 100.00% 3 100.00%



void pblk_gc_should_kick(struct pblk *pblk)
{
	struct pblk_rl *rl = &pblk->rl;
	int ret;

	/* Rates will not change that often - no need to lock update */
	ret = pblk_rl_update_rates(rl, rl->rb_budget);
	if (ret == (PBLK_RL_MID | PBLK_RL_LOW))
		pblk_gc_should_start(pblk);
	else
		pblk_gc_should_stop(pblk);
}

Contributors
Person Tokens Prop Commits CommitProp
Javier González 56 100.00% 2 100.00%
Total 56 100.00% 2 100.00%



int pblk_rl_high_thrs(struct pblk_rl *rl)
{
	return rl->high;
}

Contributors
Person Tokens Prop Commits CommitProp
Javier González 15 100.00% 2 100.00%
Total 15 100.00% 2 100.00%



int pblk_rl_low_thrs(struct pblk_rl *rl)
{
	return rl->low;
}

Contributors
Person Tokens Prop Commits CommitProp
Javier González 15 100.00% 1 100.00%
Total 15 100.00% 1 100.00%



int pblk_rl_sysfs_rate_show(struct pblk_rl *rl)
{
	return rl->rb_user_max;
}

Contributors
Person Tokens Prop Commits CommitProp
Javier González 15 100.00% 1 100.00%
Total 15 100.00% 1 100.00%



static void pblk_rl_u_timer(unsigned long data)
{
	struct pblk_rl *rl = (struct pblk_rl *)data;

	/* Release user I/O state. Protect from GC */
	smp_store_release(&rl->rb_user_active, 0);
}

Contributors
Person Tokens Prop Commits CommitProp
Javier González 33 100.00% 1 100.00%
Total 33 100.00% 1 100.00%



void pblk_rl_free(struct pblk_rl *rl)
{
	del_timer(&rl->u_timer);
}

Contributors
Person Tokens Prop Commits CommitProp
Javier González 18 100.00% 1 100.00%
Total 18 100.00% 1 100.00%



void pblk_rl_init(struct pblk_rl *rl, int budget)
{
	struct pblk *pblk = container_of(rl, struct pblk, rl);
	struct pblk_line_meta *lm = &pblk->lm;
	int min_blocks = lm->blk_per_line * PBLK_GC_RSV_LINE;
	unsigned int rb_windows;

	rl->high = rl->total_blocks / PBLK_USER_HIGH_THRS;
	rl->high_pw = get_count_order(rl->high);

	rl->low = rl->total_blocks / PBLK_USER_LOW_THRS;
	if (rl->low < min_blocks)
		rl->low = min_blocks;

	rl->rsv_blocks = min_blocks;

	/* This will always be a power-of-2 */
	rb_windows = budget / PBLK_MAX_REQ_ADDRS;
	rl->rb_windows_pw = get_count_order(rb_windows);

	/* To start with, all buffer is available to user I/O writers */
	rl->rb_budget = budget;
	rl->rb_user_max = budget;
	rl->rb_gc_max = 0;
	rl->rb_state = PBLK_RL_HIGH;

	atomic_set(&rl->rb_user_cnt, 0);
	atomic_set(&rl->rb_gc_cnt, 0);
	atomic_set(&rl->rb_space, -1);

	setup_timer(&rl->u_timer, pblk_rl_u_timer, (unsigned long)rl);

	rl->rb_user_active = 0;
	rl->rb_gc_active = 0;
}
Contributors
Person Tokens Prop Commits CommitProp
Javier González 202 100.00% 3 100.00%
Total 202 100.00% 3 100.00%

Overall Contributors
Person Tokens Prop Commits CommitProp
Javier González 955 100.00% 4 100.00%
Total 955 100.00% 4 100.00%
Directory: drivers/lightnvm

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.
Person	Tokens	Prop	Commits	CommitProp
Javier González	26	100.00%	1	100.00%
Total	26	100.00%	1	100.00%
cregit-Linux how code gets into the kernel

Release 4.14 drivers/lightnvm/pblk-rl.c

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Overall Contributors
