cregit-Linux how code gets into the kernel

Release 4.17 mm/quicklist.c

Directory: mm
// SPDX-License-Identifier: GPL-2.0
/*
 * Quicklist support.
 *
 * Quicklists are light weight lists of pages that have a defined state
 * on alloc and free. Pages must be in the quicklist specific defined state
 * (zero by default) when the page is freed. It seems that the initial idea
 * for such lists first came from Dave Miller and then various other people
 * improved on it.
 *
 * Copyright (C) 2007 SGI,
 *      Christoph Lameter <cl@linux.com>
 *              Generalized, added support for multiple lists and
 *              constructors / destructors.
 */
#include <linux/kernel.h>

#include <linux/gfp.h>
#include <linux/mm.h>
#include <linux/mmzone.h>
#include <linux/quicklist.h>

DEFINE_PER_CPU(struct quicklist [CONFIG_NR_QUICK], quicklist);


#define FRACTION_OF_NODE_MEM	16


static unsigned long max_pages(unsigned long min_pages) { unsigned long node_free_pages, max; int node = numa_node_id(); struct zone *zones = NODE_DATA(node)->node_zones; int num_cpus_on_node; node_free_pages = #ifdef CONFIG_ZONE_DMA zone_page_state(&zones[ZONE_DMA], NR_FREE_PAGES) + #endif #ifdef CONFIG_ZONE_DMA32 zone_page_state(&zones[ZONE_DMA32], NR_FREE_PAGES) + #endif zone_page_state(&zones[ZONE_NORMAL], NR_FREE_PAGES); max = node_free_pages / FRACTION_OF_NODE_MEM; num_cpus_on_node = cpumask_weight(cpumask_of_node(node)); max /= num_cpus_on_node; return max(max, min_pages); }

Contributors

PersonTokensPropCommitsCommitProp
Christoph Lameter8778.38%250.00%
Motohiro Kosaki1917.12%125.00%
Rusty Russell54.50%125.00%
Total111100.00%4100.00%


static long min_pages_to_free(struct quicklist *q, unsigned long min_pages, long max_free) { long pages_to_free; pages_to_free = q->nr_pages - max_pages(min_pages); return min(pages_to_free, max_free); }

Contributors

PersonTokensPropCommitsCommitProp
Christoph Lameter40100.00%1100.00%
Total40100.00%1100.00%

/* * Trim down the number of pages in the quicklist */
void quicklist_trim(int nr, void (*dtor)(void *), unsigned long min_pages, unsigned long max_free) { long pages_to_free; struct quicklist *q; q = &get_cpu_var(quicklist)[nr]; if (q->nr_pages > min_pages) { pages_to_free = min_pages_to_free(q, min_pages, max_free); while (pages_to_free > 0) { /* * We pass a gfp_t of 0 to quicklist_alloc here * because we will never call into the page allocator. */ void *p = quicklist_alloc(nr, 0, NULL); if (dtor) dtor(p); free_page((unsigned long)p); pages_to_free--; } } put_cpu_var(quicklist); }

Contributors

PersonTokensPropCommitsCommitProp
Christoph Lameter114100.00%1100.00%
Total114100.00%1100.00%


unsigned long quicklist_total_size(void) { unsigned long count = 0; int cpu; struct quicklist *ql, *q; for_each_online_cpu(cpu) { ql = per_cpu(quicklist, cpu); for (q = ql; q < ql + CONFIG_NR_QUICK; q++) count += q->nr_pages; } return count; }

Contributors

PersonTokensPropCommitsCommitProp
Christoph Lameter64100.00%1100.00%
Total64100.00%1100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Christoph Lameter33191.44%337.50%
Motohiro Kosaki195.25%112.50%
Tejun Heo61.66%225.00%
Rusty Russell51.38%112.50%
Greg Kroah-Hartman10.28%112.50%
Total362100.00%8100.00%
Directory: mm
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