| Message ID | 20200311034441.23243-2-jaewon31.kim@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | meminfo: introduce extra meminfo | expand |
On (20/03/11 12:44), Jaewon Kim wrote: [..] > +#define NAME_SIZE 15 > +#define NAME_BUF_SIZE (NAME_SIZE + 2) /* ':' and '\0' */ > + > +struct extra_meminfo { > + struct list_head list; > + atomic_long_t *val; > + int shift_for_page; > + char name[NAME_BUF_SIZE]; > + char name_pad[NAME_BUF_SIZE]; > +}; > + > +int register_extra_meminfo(atomic_long_t *val, int shift, const char *name) > +{ > + struct extra_meminfo *meminfo, *memtemp; > + int len; > + int error = 0; > + > + meminfo = kzalloc(sizeof(*meminfo), GFP_KERNEL); > + if (!meminfo) { > + error = -ENOMEM; > + goto out; > + } > + > + meminfo->val = val; > + meminfo->shift_for_page = shift; > + strncpy(meminfo->name, name, NAME_SIZE); > + len = strlen(meminfo->name); > + meminfo->name[len] = ':'; > + strncpy(meminfo->name_pad, meminfo->name, NAME_BUF_SIZE); What happens if there is no NULL byte among the first NAME_SIZE bytes of passed `name'? [..] > + spin_lock(&meminfo_lock); Does this need to be a spinlock? -ss
On (20/03/11 15:18), Sergey Senozhatsky wrote: > On (20/03/11 12:44), Jaewon Kim wrote: > [..] > > +#define NAME_SIZE 15 > > +#define NAME_BUF_SIZE (NAME_SIZE + 2) /* ':' and '\0' */ > > + > > +struct extra_meminfo { > > + struct list_head list; > > + atomic_long_t *val; > > + int shift_for_page; > > + char name[NAME_BUF_SIZE]; > > + char name_pad[NAME_BUF_SIZE]; > > +}; > > + > > +int register_extra_meminfo(atomic_long_t *val, int shift, const char *name) > > +{ > > + struct extra_meminfo *meminfo, *memtemp; > > + int len; > > + int error = 0; > > + > > + meminfo = kzalloc(sizeof(*meminfo), GFP_KERNEL); > > + if (!meminfo) { > > + error = -ENOMEM; > > + goto out; > > + } > > + > > + meminfo->val = val; > > + meminfo->shift_for_page = shift; > > + strncpy(meminfo->name, name, NAME_SIZE); > > + len = strlen(meminfo->name); > > + meminfo->name[len] = ':'; > > + strncpy(meminfo->name_pad, meminfo->name, NAME_BUF_SIZE); > > What happens if there is no NULL byte among the first NAME_SIZE bytes > of passed `name'? Ah. The buffer size is NAME_BUF_SIZE, so should be fine. -ss
On 2020년 03월 11일 15:25, Sergey Senozhatsky wrote: > On (20/03/11 15:18), Sergey Senozhatsky wrote: >> On (20/03/11 12:44), Jaewon Kim wrote: >> [..] >>> +#define NAME_SIZE 15 >>> +#define NAME_BUF_SIZE (NAME_SIZE + 2) /* ':' and '\0' */ >>> + >>> +struct extra_meminfo { >>> + struct list_head list; >>> + atomic_long_t *val; >>> + int shift_for_page; >>> + char name[NAME_BUF_SIZE]; >>> + char name_pad[NAME_BUF_SIZE]; >>> +}; >>> + >>> +int register_extra_meminfo(atomic_long_t *val, int shift, const char *name) >>> +{ >>> + struct extra_meminfo *meminfo, *memtemp; >>> + int len; >>> + int error = 0; >>> + >>> + meminfo = kzalloc(sizeof(*meminfo), GFP_KERNEL); >>> + if (!meminfo) { >>> + error = -ENOMEM; >>> + goto out; >>> + } >>> + >>> + meminfo->val = val; >>> + meminfo->shift_for_page = shift; >>> + strncpy(meminfo->name, name, NAME_SIZE); >>> + len = strlen(meminfo->name); >>> + meminfo->name[len] = ':'; >>> + strncpy(meminfo->name_pad, meminfo->name, NAME_BUF_SIZE); >> What happens if there is no NULL byte among the first NAME_SIZE bytes >> of passed `name'? > Ah. The buffer size is NAME_BUF_SIZE, so should be fine. > > -ss Hello yes correct. For your comment of 'spinlock', it may be changed to other lock like rw semaphore. I think there are just couple of writers compared to many readers. Thank you for your comment. > >
On Wed, Mar 11, 2020 at 12:44:39PM +0900, Jaewon Kim wrote: > Provide APIs to drivers so that they can show its memory usage on > /proc/meminfo. > > int register_extra_meminfo(atomic_long_t *val, int shift, > const char *name); > int unregister_extra_meminfo(atomic_long_t *val); > + show_val_kb(m, memtemp->name_pad, nr_page); I have 3 issues. Can this be printed without "KB" piece and without useless whitespace, like /proc/vmstat does? I don't know how do you parse /proc/meminfo. Do you search for specific string or do you use some kind of map[k] = v interface? 2) zsmalloc can create top-level symlink and resolve it to necessary value. It will be only 1 readlink(2) system call to fetch it. 3) android can do the same For simple values there is no need to register stuff and create mini subsystems. /proc/alexey
On 2020년 03월 12일 02:35, Alexey Dobriyan wrote: > On Wed, Mar 11, 2020 at 12:44:39PM +0900, Jaewon Kim wrote: >> Provide APIs to drivers so that they can show its memory usage on >> /proc/meminfo. >> >> int register_extra_meminfo(atomic_long_t *val, int shift, >> const char *name); >> int unregister_extra_meminfo(atomic_long_t *val); >> + show_val_kb(m, memtemp->name_pad, nr_page); > I have 3 issues. > > Can this be printed without "KB" piece and without useless whitespace, > like /proc/vmstat does? > > I don't know how do you parse /proc/meminfo. > Do you search for specific string or do you use some kind of map[k] = v > interface? If need, I can remove KB. but show_free_areas also seems to print KB for some stats. And I intentionally added : and space to be same format like others in /proc/meminfo. show_val_kb(m, "MemTotal: ", i.totalram); > > 2) zsmalloc can create top-level symlink and resolve it to necessary value. > It will be only 1 readlink(2) system call to fetch it. Yes it could be done by userspace readlink systemcall. But I wanted to see all huge memory stats on one node of /proc/meminfo. > > 3) android can do the same > > For simple values there is no need to register stuff and create > mini subsystems. > > /proc/alexey OK as Leon Romanovsky said, I may be able to move other node of /proc/meminfo_extra. Please let me know if it still have a point to be reviewed. Thank you > >
diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c index 8c1f1bb1a5ce..12b1f77b091b 100644 --- a/fs/proc/meminfo.c +++ b/fs/proc/meminfo.c @@ -13,6 +13,7 @@ #include <linux/vmstat.h> #include <linux/atomic.h> #include <linux/vmalloc.h> +#include <linux/slab.h> #ifdef CONFIG_CMA #include <linux/cma.h> #endif @@ -30,6 +31,106 @@ static void show_val_kb(struct seq_file *m, const char *s, unsigned long num) seq_write(m, " kB\n", 4); } +static LIST_HEAD(meminfo_head); +static DEFINE_SPINLOCK(meminfo_lock); + +#define NAME_SIZE 15 +#define NAME_BUF_SIZE (NAME_SIZE + 2) /* ':' and '\0' */ + +struct extra_meminfo { + struct list_head list; + atomic_long_t *val; + int shift_for_page; + char name[NAME_BUF_SIZE]; + char name_pad[NAME_BUF_SIZE]; +}; + +int register_extra_meminfo(atomic_long_t *val, int shift, const char *name) +{ + struct extra_meminfo *meminfo, *memtemp; + int len; + int error = 0; + + meminfo = kzalloc(sizeof(*meminfo), GFP_KERNEL); + if (!meminfo) { + error = -ENOMEM; + goto out; + } + + meminfo->val = val; + meminfo->shift_for_page = shift; + strncpy(meminfo->name, name, NAME_SIZE); + len = strlen(meminfo->name); + meminfo->name[len] = ':'; + strncpy(meminfo->name_pad, meminfo->name, NAME_BUF_SIZE); + while (++len < NAME_BUF_SIZE - 1) + meminfo->name_pad[len] = ' '; + + spin_lock(&meminfo_lock); + list_for_each_entry(memtemp, &meminfo_head, list) { + if (memtemp->val == val) { + error = -EINVAL; + break; + } + } + if (!error) + list_add_tail(&meminfo->list, &meminfo_head); + spin_unlock(&meminfo_lock); + if (error) + kfree(meminfo); +out: + + return error; +} +EXPORT_SYMBOL(register_extra_meminfo); + +int unregister_extra_meminfo(atomic_long_t *val) +{ + struct extra_meminfo *memtemp, *memtemp2; + int error = -EINVAL; + + spin_lock(&meminfo_lock); + list_for_each_entry_safe(memtemp, memtemp2, &meminfo_head, list) { + if (memtemp->val == val) { + list_del(&memtemp->list); + error = 0; + break; + } + } + spin_unlock(&meminfo_lock); + kfree(memtemp); + + return error; +} +EXPORT_SYMBOL(unregister_extra_meminfo); + +static void __extra_meminfo(struct seq_file *m) +{ + struct extra_meminfo *memtemp; + unsigned long nr_page; + + spin_lock(&meminfo_lock); + list_for_each_entry(memtemp, &meminfo_head, list) { + nr_page = (unsigned long)atomic_long_read(memtemp->val); + nr_page = nr_page >> memtemp->shift_for_page; + if (m) + show_val_kb(m, memtemp->name_pad, nr_page); + else + pr_cont("%s%lukB ", memtemp->name, nr_page); + } + spin_unlock(&meminfo_lock); +} + +void extra_meminfo_log(void) +{ + __extra_meminfo(NULL); +} + +static void extra_meminfo_proc(struct seq_file *m) +{ + __extra_meminfo(m); +} + static int meminfo_proc_show(struct seq_file *m, void *v) { struct sysinfo i; @@ -148,6 +249,8 @@ static int meminfo_proc_show(struct seq_file *m, void *v) arch_report_meminfo(m); + extra_meminfo_proc(m); + return 0; } diff --git a/include/linux/mm.h b/include/linux/mm.h index c54fb96cb1e6..457570ddd17c 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2902,6 +2902,10 @@ void __init setup_nr_node_ids(void); static inline void setup_nr_node_ids(void) {} #endif +void extra_meminfo_log(void); +int register_extra_meminfo(atomic_long_t *val, int shift, const char *name); +int unregister_extra_meminfo(atomic_long_t *val); + extern int memcmp_pages(struct page *page1, struct page *page2); static inline int pages_identical(struct page *page1, struct page *page2) diff --git a/lib/show_mem.c b/lib/show_mem.c index 1c26c14ffbb9..48be5afaca0a 100644 --- a/lib/show_mem.c +++ b/lib/show_mem.c @@ -14,6 +14,7 @@ void show_mem(unsigned int filter, nodemask_t *nodemask) unsigned long total = 0, reserved = 0, highmem = 0; printk("Mem-Info:\n"); + extra_meminfo_log(); show_free_areas(filter, nodemask); for_each_online_pgdat(pgdat) {
Provide APIs to drivers so that they can show its memory usage on /proc/meminfo. int register_extra_meminfo(atomic_long_t *val, int shift, const char *name); int unregister_extra_meminfo(atomic_long_t *val); Signed-off-by: Jaewon Kim <jaewon31.kim@samsung.com> --- fs/proc/meminfo.c | 103 +++++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/mm.h | 4 +++ lib/show_mem.c | 1 + 3 files changed, 108 insertions(+)