Messages in this thread Patch in this message | | | From | Byungchul Park <> | Subject | [v3 3/3] mm, migrc: Add a sysctl knob to enable/disable MIGRC mechanism | Date | Mon, 30 Oct 2023 16:25:40 +0900 |
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Add a sysctl knob, '/proc/sys/vm/migrc_enable' to switch on/off migrc.
Signed-off-by: Byungchul Park <byungchul@sk.com> --- mm/migrate.c | 44 +++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 43 insertions(+), 1 deletion(-)
diff --git a/mm/migrate.c b/mm/migrate.c index 76278eca8417..f6bbdc2d4fb1 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -58,6 +58,48 @@ #include "internal.h" #ifdef CONFIG_MIGRC +static int sysctl_migrc_enable = 1; +#ifdef CONFIG_SYSCTL +static int sysctl_migrc_enable_handler(struct ctl_table *table, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + struct ctl_table t; + int err; + int enabled = sysctl_migrc_enable; + + if (write && !capable(CAP_SYS_ADMIN)) + return -EPERM; + + t = *table; + t.data = &enabled; + err = proc_dointvec_minmax(&t, write, buffer, lenp, ppos); + if (err < 0) + return err; + if (write) + sysctl_migrc_enable = enabled; + return err; +} + +static struct ctl_table migrc_sysctls[] = { + { + .procname = "migrc_enable", + .data = NULL, /* filled in by handler */ + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = sysctl_migrc_enable_handler, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, + {} +}; + +static int __init migrc_sysctl_init(void) +{ + register_sysctl_init("vm", migrc_sysctls); + return 0; +} +late_initcall(migrc_sysctl_init); +#endif atomic_t migrc_gen; @@ -242,7 +284,7 @@ static inline bool migrc_stopped_pending(void) static bool can_migrc_system(void) { - return !migrc_stopped_pending(); + return sysctl_migrc_enable && !migrc_stopped_pending(); } #else static inline void migrc_mark_folios(struct folio *fsrc, struct folio *fdst) {} -- 2.17.1
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