From: Matt Mackall This interface is primarily useful for doing memory profiling and not much use on deployed embedded boxes. Make it optional. Together with /proc/pid/smaps, this save a few K. Signed-off-by: Matt Mackall Cc: Jeremy Fitzhardinge Acked-by: David Rientjes Signed-off-by: Andrew Morton --- fs/proc/base.c | 4 ++++ fs/proc/task_mmu.c | 2 ++ init/Kconfig | 9 +++++++++ 3 files changed, 15 insertions(+) diff -puN fs/proc/base.c~maps2-make-proc-pid-clear_refs-option-under-config_embedded fs/proc/base.c --- a/fs/proc/base.c~maps2-make-proc-pid-clear_refs-option-under-config_embedded +++ a/fs/proc/base.c @@ -2033,7 +2033,9 @@ static const struct pid_entry tgid_base_ REG("mounts", S_IRUGO, mounts), REG("mountstats", S_IRUSR, mountstats), #ifdef CONFIG_MMU +#ifdef CONFIG_PROC_CLEAR_REFS REG("clear_refs", S_IWUSR, clear_refs), +#endif #ifdef CONFIG_PROC_SMAPS REG("smaps", S_IRUGO, smaps), #endif @@ -2321,7 +2323,9 @@ static const struct pid_entry tid_base_s LNK("exe", exe), REG("mounts", S_IRUGO, mounts), #ifdef CONFIG_MMU +#ifdef CONFIG_PROC_CLEAR_REFS REG("clear_refs", S_IWUSR, clear_refs), +#endif #ifdef CONFIG_PROC_SMAPS REG("smaps", S_IRUGO, smaps), #endif diff -puN fs/proc/task_mmu.c~maps2-make-proc-pid-clear_refs-option-under-config_embedded fs/proc/task_mmu.c --- a/fs/proc/task_mmu.c~maps2-make-proc-pid-clear_refs-option-under-config_embedded +++ a/fs/proc/task_mmu.c @@ -424,6 +424,7 @@ const struct file_operations proc_smaps_ }; #endif +#ifdef CONFIG_PROC_CLEAR_REFS static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, void *private) { @@ -493,6 +494,7 @@ static ssize_t clear_refs_write(struct f const struct file_operations proc_clear_refs_operations = { .write = clear_refs_write, }; +#endif #ifdef CONFIG_NUMA extern int show_numa_map(struct seq_file *m, void *v); diff -puN init/Kconfig~maps2-make-proc-pid-clear_refs-option-under-config_embedded init/Kconfig --- a/init/Kconfig~maps2-make-proc-pid-clear_refs-option-under-config_embedded +++ a/init/Kconfig @@ -582,6 +582,15 @@ config PROC_SMAPS shared memory per mapping. Disabling this interface will reduce the size of the kernel for small machines. +config PROC_CLEAR_REFS + default y + bool "Enable /proc/pid/clear_refs support" if EMBEDDED && PROC_FS && MMU + help + The /proc/pid/clear_refs interface allows clearing the + referenced bits on a process's memory maps to allow monitoring + working set size. Disabling this interface will reduce + the size of the kernel for small machines. + endmenu # General setup config RT_MUTEXES _