tools/testing/selftests/mm/thp_settings.c

Source file repositories/reference/linux-study-clean/tools/testing/selftests/mm/thp_settings.c

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/mm/thp_settings.c
Extension
.c
Size
8710 bytes
Lines
373
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

if (!((1 << i) & orders)) {
			settings->hugepages[i].enabled = THP_NEVER;
			continue;
		}
		snprintf(path, PATH_MAX, "hugepages-%ukB/enabled",
			(getpagesize() >> 10) << i);
		settings->hugepages[i].enabled =
			thp_read_string(path, thp_enabled_strings);
	}

	for (i = 0; i < NR_ORDERS; i++) {
		if (!((1 << i) & shmem_orders)) {
			settings->shmem_hugepages[i].enabled = SHMEM_NEVER;
			continue;
		}
		snprintf(path, PATH_MAX, "hugepages-%ukB/shmem_enabled",
			(getpagesize() >> 10) << i);
		settings->shmem_hugepages[i].enabled =
			thp_read_string(path, shmem_enabled_strings);
	}
}

void thp_write_settings(struct thp_settings *settings)
{
	struct khugepaged_settings *khugepaged = &settings->khugepaged;
	unsigned long orders = thp_supported_orders();
	unsigned long shmem_orders = thp_shmem_supported_orders();
	char path[PATH_MAX];
	int enabled;
	int i;

	thp_write_string("enabled", thp_enabled_strings[settings->thp_enabled]);
	thp_write_string("defrag", thp_defrag_strings[settings->thp_defrag]);
	thp_write_string("shmem_enabled",
			shmem_enabled_strings[settings->shmem_enabled]);
	thp_write_num("use_zero_page", settings->use_zero_page);

	thp_write_num("khugepaged/defrag", khugepaged->defrag);
	thp_write_num("khugepaged/alloc_sleep_millisecs",
			khugepaged->alloc_sleep_millisecs);
	thp_write_num("khugepaged/scan_sleep_millisecs",
			khugepaged->scan_sleep_millisecs);
	thp_write_num("khugepaged/max_ptes_none", khugepaged->max_ptes_none);
	thp_write_num("khugepaged/max_ptes_swap", khugepaged->max_ptes_swap);
	thp_write_num("khugepaged/max_ptes_shared", khugepaged->max_ptes_shared);
	thp_write_num("khugepaged/pages_to_scan", khugepaged->pages_to_scan);

	if (dev_queue_read_ahead_path[0])
		write_num(dev_queue_read_ahead_path, settings->read_ahead_kb);

	for (i = 0; i < NR_ORDERS; i++) {
		if (!((1 << i) & orders))
			continue;
		snprintf(path, PATH_MAX, "hugepages-%ukB/enabled",
			(getpagesize() >> 10) << i);
		enabled = settings->hugepages[i].enabled;
		thp_write_string(path, thp_enabled_strings[enabled]);
	}

	for (i = 0; i < NR_ORDERS; i++) {
		if (!((1 << i) & shmem_orders))
			continue;
		snprintf(path, PATH_MAX, "hugepages-%ukB/shmem_enabled",
			(getpagesize() >> 10) << i);
		enabled = settings->shmem_hugepages[i].enabled;
		thp_write_string(path, shmem_enabled_strings[enabled]);
	}
}

struct thp_settings *thp_current_settings(void)
{
	if (!settings_index) {
		printf("Fail: No settings set");
		exit(EXIT_FAILURE);
	}
	return settings_stack + settings_index - 1;
}

void thp_push_settings(struct thp_settings *settings)
{
	if (settings_index >= MAX_SETTINGS_DEPTH) {
		printf("Fail: Settings stack exceeded");
		exit(EXIT_FAILURE);
	}
	settings_stack[settings_index++] = *settings;
	thp_write_settings(thp_current_settings());
}

void thp_pop_settings(void)
{

Annotation

Implementation Notes