Merge tag 'reset-fixes-for-v5.19' of git://git.pengutronix.de/pza/linux into arm...

[platform/kernel/linux-starfive.git] / mm / page-writeback.c

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index fa1117d..55c2776 100644 (file)
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -70,30 +70,30 @@ static long ratelimit_pages = 32;
 /*
  * Start background writeback (via writeback threads) at this percentage
  */
-int dirty_background_ratio = 10;
+static int dirty_background_ratio = 10;
 
 /*
  * dirty_background_bytes starts at 0 (disabled) so that it is a function of
  * dirty_background_ratio * the amount of dirtyable memory
  */
-unsigned long dirty_background_bytes;
+static unsigned long dirty_background_bytes;
 
 /*
  * free highmem will not be subtracted from the total free memory
  * for calculating free ratios if vm_highmem_is_dirtyable is true
  */
-int vm_highmem_is_dirtyable;
+static int vm_highmem_is_dirtyable;
 
 /*
  * The generator of dirty data starts writeback at this percentage
  */
-int vm_dirty_ratio = 20;
+static int vm_dirty_ratio = 20;
 
 /*
  * vm_dirty_bytes starts at 0 (disabled) so that it is a function of
  * vm_dirty_ratio * the amount of dirtyable memory
  */
-unsigned long vm_dirty_bytes;
+static unsigned long vm_dirty_bytes;
 
 /*
  * The interval between `kupdate'-style writebacks
@@ -491,7 +491,8 @@ bool node_dirty_ok(struct pglist_data *pgdat)
        return nr_pages <= limit;
 }
 
-int dirty_background_ratio_handler(struct ctl_table *table, int write,
+#ifdef CONFIG_SYSCTL
+static int dirty_background_ratio_handler(struct ctl_table *table, int write,
                void *buffer, size_t *lenp, loff_t *ppos)
 {
        int ret;
@@ -502,7 +503,7 @@ int dirty_background_ratio_handler(struct ctl_table *table, int write,
        return ret;
 }
 
-int dirty_background_bytes_handler(struct ctl_table *table, int write,
+static int dirty_background_bytes_handler(struct ctl_table *table, int write,
                void *buffer, size_t *lenp, loff_t *ppos)
 {
        int ret;
@@ -513,7 +514,7 @@ int dirty_background_bytes_handler(struct ctl_table *table, int write,
        return ret;
 }
 
-int dirty_ratio_handler(struct ctl_table *table, int write, void *buffer,
+static int dirty_ratio_handler(struct ctl_table *table, int write, void *buffer,
                size_t *lenp, loff_t *ppos)
 {
        int old_ratio = vm_dirty_ratio;
@@ -527,7 +528,7 @@ int dirty_ratio_handler(struct ctl_table *table, int write, void *buffer,
        return ret;
 }
 
-int dirty_bytes_handler(struct ctl_table *table, int write,
+static int dirty_bytes_handler(struct ctl_table *table, int write,
                void *buffer, size_t *lenp, loff_t *ppos)
 {
        unsigned long old_bytes = vm_dirty_bytes;
@@ -540,6 +541,7 @@ int dirty_bytes_handler(struct ctl_table *table, int write,
        }
        return ret;
 }
+#endif
 
 static unsigned long wp_next_time(unsigned long cur_time)
 {
@@ -650,18 +652,25 @@ static unsigned int bdi_min_ratio;
 
 int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio)
 {
+       unsigned int delta;
        int ret = 0;
 
        spin_lock_bh(&bdi_lock);
        if (min_ratio > bdi->max_ratio) {
                ret = -EINVAL;
        } else {
-               min_ratio -= bdi->min_ratio;
-               if (bdi_min_ratio + min_ratio < 100) {
-                       bdi_min_ratio += min_ratio;
-                       bdi->min_ratio += min_ratio;
+               if (min_ratio < bdi->min_ratio) {
+                       delta = bdi->min_ratio - min_ratio;
+                       bdi_min_ratio -= delta;
+                       bdi->min_ratio = min_ratio;
                } else {
-                       ret = -EINVAL;
+                       delta = min_ratio - bdi->min_ratio;
+                       if (bdi_min_ratio + delta < 100) {
+                               bdi_min_ratio += delta;
+                               bdi->min_ratio = min_ratio;
+                       } else {
+                               ret = -EINVAL;
+                       }
                }
        }
        spin_unlock_bh(&bdi_lock);
@@ -1981,10 +1990,11 @@ bool wb_over_bg_thresh(struct bdi_writeback *wb)
        return false;
 }
 
+#ifdef CONFIG_SYSCTL
 /*
  * sysctl handler for /proc/sys/vm/dirty_writeback_centisecs
  */
-int dirty_writeback_centisecs_handler(struct ctl_table *table, int write,
+static int dirty_writeback_centisecs_handler(struct ctl_table *table, int write,
                void *buffer, size_t *length, loff_t *ppos)
 {
        unsigned int old_interval = dirty_writeback_interval;
@@ -2005,6 +2015,7 @@ int dirty_writeback_centisecs_handler(struct ctl_table *table, int write,
 
        return ret;
 }
+#endif
 
 void laptop_mode_timer_fn(struct timer_list *t)
 {
@@ -2069,6 +2080,83 @@ static int page_writeback_cpu_online(unsigned int cpu)
        return 0;
 }
 
+#ifdef CONFIG_SYSCTL
+
+/* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
+static const unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
+
+static struct ctl_table vm_page_writeback_sysctls[] = {
+       {
+               .procname   = "dirty_background_ratio",
+               .data       = &dirty_background_ratio,
+               .maxlen     = sizeof(dirty_background_ratio),
+               .mode       = 0644,
+               .proc_handler   = dirty_background_ratio_handler,
+               .extra1     = SYSCTL_ZERO,
+               .extra2     = SYSCTL_ONE_HUNDRED,
+       },
+       {
+               .procname   = "dirty_background_bytes",
+               .data       = &dirty_background_bytes,
+               .maxlen     = sizeof(dirty_background_bytes),
+               .mode       = 0644,
+               .proc_handler   = dirty_background_bytes_handler,
+               .extra1     = SYSCTL_LONG_ONE,
+       },
+       {
+               .procname   = "dirty_ratio",
+               .data       = &vm_dirty_ratio,
+               .maxlen     = sizeof(vm_dirty_ratio),
+               .mode       = 0644,
+               .proc_handler   = dirty_ratio_handler,
+               .extra1     = SYSCTL_ZERO,
+               .extra2     = SYSCTL_ONE_HUNDRED,
+       },
+       {
+               .procname   = "dirty_bytes",
+               .data       = &vm_dirty_bytes,
+               .maxlen     = sizeof(vm_dirty_bytes),
+               .mode       = 0644,
+               .proc_handler   = dirty_bytes_handler,
+               .extra1     = (void *)&dirty_bytes_min,
+       },
+       {
+               .procname   = "dirty_writeback_centisecs",
+               .data       = &dirty_writeback_interval,
+               .maxlen     = sizeof(dirty_writeback_interval),
+               .mode       = 0644,
+               .proc_handler   = dirty_writeback_centisecs_handler,
+       },
+       {
+               .procname   = "dirty_expire_centisecs",
+               .data       = &dirty_expire_interval,
+               .maxlen     = sizeof(dirty_expire_interval),
+               .mode       = 0644,
+               .proc_handler   = proc_dointvec_minmax,
+               .extra1     = SYSCTL_ZERO,
+       },
+#ifdef CONFIG_HIGHMEM
+       {
+               .procname       = "highmem_is_dirtyable",
+               .data           = &vm_highmem_is_dirtyable,
+               .maxlen         = sizeof(vm_highmem_is_dirtyable),
+               .mode           = 0644,
+               .proc_handler   = proc_dointvec_minmax,
+               .extra1         = SYSCTL_ZERO,
+               .extra2         = SYSCTL_ONE,
+       },
+#endif
+       {
+               .procname       = "laptop_mode",
+               .data           = &laptop_mode,
+               .maxlen         = sizeof(laptop_mode),
+               .mode           = 0644,
+               .proc_handler   = proc_dointvec_jiffies,
+       },
+       {}
+};
+#endif
+
 /*
  * Called early on to tune the page writeback dirty limits.
  *
@@ -2093,6 +2181,9 @@ void __init page_writeback_init(void)
                          page_writeback_cpu_online, NULL);
        cpuhp_setup_state(CPUHP_MM_WRITEBACK_DEAD, "mm/writeback:dead", NULL,
                          page_writeback_cpu_online);
+#ifdef CONFIG_SYSCTL
+       register_sysctl_init("vm", vm_page_writeback_sysctls);
+#endif
 }
 
 /**