Commit d2b43658 authored by Arnd Bergmann's avatar Arnd Bergmann Committed by Tejun Heo

cpuset: Replace all instances of time_t with time64_t

The following patch replaces all instances of time_t with time64_t i.e.
change the type used for representing time from 32-bit to 64-bit. All
32-bit kernels to date use a signed 32-bit time_t type, which can only
represent time until January 2038. Since embedded systems running 32-bit
Linux are going to survive beyond that date, we have to change all
current uses, in a backwards compatible way.

The patch also changes the function get_seconds() that returns a 32-bit
integer to ktime_get_seconds() that returns seconds as 64-bit integer.

The patch changes the type of ticks from time_t to u32. We keep ticks as
32-bits as the function uses 32-bit arithmetic which would prove less
expensive than 64-bit arithmetic and the function is expected to be
called atleast once every 32 seconds.
Signed-off-by: default avatarHeena Sirwani <heenasirwani@gmail.com>
Reviewed-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 6c292092
......@@ -51,6 +51,7 @@
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/time.h>
#include <linux/time64.h>
#include <linux/backing-dev.h>
#include <linux/sort.h>
......@@ -68,7 +69,7 @@ struct static_key cpusets_enabled_key __read_mostly = STATIC_KEY_INIT_FALSE;
struct fmeter {
int cnt; /* unprocessed events count */
int val; /* most recent output value */
time_t time; /* clock (secs) when val computed */
time64_t time; /* clock (secs) when val computed */
spinlock_t lock; /* guards read or write of above */
};
......@@ -1374,7 +1375,7 @@ out:
*/
#define FM_COEF 933 /* coefficient for half-life of 10 secs */
#define FM_MAXTICKS ((time_t)99) /* useless computing more ticks than this */
#define FM_MAXTICKS ((u32)99) /* useless computing more ticks than this */
#define FM_MAXCNT 1000000 /* limit cnt to avoid overflow */
#define FM_SCALE 1000 /* faux fixed point scale */
......@@ -1390,8 +1391,11 @@ static void fmeter_init(struct fmeter *fmp)
/* Internal meter update - process cnt events and update value */
static void fmeter_update(struct fmeter *fmp)
{
time_t now = get_seconds();
time_t ticks = now - fmp->time;
time64_t now;
u32 ticks;
now = ktime_get_seconds();
ticks = now - fmp->time;
if (ticks == 0)
return;
......
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