Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 74a622be authored by Thomas Gleixner's avatar Thomas Gleixner Committed by John Stultz
Browse files

ia64: vsyscall: Use seqcount instead of seqlock 



The update of the vdso data happens under xtime_lock, so adding a
nested lock is pointless. Just use a seqcount to sync the readers.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: default avatarJohn Stultz <john.stultz@linaro.org>
parent 2ab51657

arch/ia64/kernel/asm-offsets.c

+2 −2
Original line number Diff line number Diff line
@@ -269,8 +269,8 @@ void foo(void) 
	BLANK();



	/* used by fsys_gettimeofday in arch/ia64/kernel/fsys.S */

	DEFINE(IA64_GTOD_LOCK_OFFSET,

		offsetof (struct fsyscall_gtod_data_t, lock));

	DEFINE(IA64_GTOD_SEQ_OFFSET,

		offsetof (struct fsyscall_gtod_data_t, seq);

	DEFINE(IA64_GTOD_WALL_TIME_OFFSET,

		offsetof (struct fsyscall_gtod_data_t, wall_time));

	DEFINE(IA64_GTOD_MONO_TIME_OFFSET,

arch/ia64/kernel/fsys.S

+1 −1
Original line number Diff line number Diff line
@@ -174,7 +174,7 @@ ENTRY(fsys_set_tid_address) 
	FSYS_RETURN

END(fsys_set_tid_address)



#if IA64_GTOD_LOCK_OFFSET !=0

#if IA64_GTOD_SEQ_OFFSET !=0

#error fsys_gettimeofday incompatible with changes to struct fsyscall_gtod_data_t

#endif

#if IA64_ITC_JITTER_OFFSET !=0

arch/ia64/kernel/fsyscall_gtod_data.h

+1 −1
Original line number Diff line number Diff line
@@ -6,7 +6,7 @@ 
 */



struct fsyscall_gtod_data_t {

	seqlock_t	lock;

	seqcount_t	seq;

	struct timespec	wall_time;

	struct timespec monotonic_time;

	cycle_t		clk_mask;

arch/ia64/kernel/time.c

+3 −7
Original line number Diff line number Diff line
@@ -35,9 +35,7 @@ 


static cycle_t itc_get_cycles(struct clocksource *cs);



struct fsyscall_gtod_data_t fsyscall_gtod_data = {

	.lock = __SEQLOCK_UNLOCKED(fsyscall_gtod_data.lock),

};

struct fsyscall_gtod_data_t fsyscall_gtod_data;



struct itc_jitter_data_t itc_jitter_data;
@@ -460,9 +458,7 @@ void update_vsyscall_tz(void) 
void update_vsyscall(struct timespec *wall, struct timespec *wtm,

			struct clocksource *c, u32 mult)

{

        unsigned long flags;



        write_seqlock_irqsave(&fsyscall_gtod_data.lock, flags);

	write_seqcount_begin(&fsyscall_gtod_data.seq);



        /* copy fsyscall clock data */

        fsyscall_gtod_data.clk_mask = c->mask;
@@ -485,6 +481,6 @@ void update_vsyscall(struct timespec *wall, struct timespec *wtm, 
		fsyscall_gtod_data.monotonic_time.tv_sec++;

	}



        write_sequnlock_irqrestore(&fsyscall_gtod_data.lock, flags);

	write_seqcount_end(&fsyscall_gtod_data.seq);

}