s390/vdso: ectg gettime support for CLOCK_THREAD_CPUTIME_ID

The code to use the ECTG instruction to calculate the cputime for the
current thread is currently used only for the per-thread CPU-clock
with the clockid -2 (PID=0, VIRT=1). Use the same code for the clockid
CLOCK_THREAD_CPUTIME_ID to speed up the more common clockid as well.

Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c
index 496116c..e4c99a1 100644 (file)
--- a/arch/s390/kernel/asm-offsets.c
+++ b/arch/s390/kernel/asm-offsets.c
@@ -72,6 +72,7 @@ int main(void)
        /* constants used by the vdso */
        DEFINE(__CLOCK_REALTIME, CLOCK_REALTIME);
        DEFINE(__CLOCK_MONOTONIC, CLOCK_MONOTONIC);
+       DEFINE(__CLOCK_THREAD_CPUTIME_ID, CLOCK_THREAD_CPUTIME_ID);
        DEFINE(__CLOCK_REALTIME_RES, MONOTONIC_RES_NSEC);
        BLANK();
        /* idle data offsets */

diff --git a/arch/s390/kernel/vdso64/clock_getres.S b/arch/s390/kernel/vdso64/clock_getres.S
index 176e1f7..34deba7 100644 (file)
--- a/arch/s390/kernel/vdso64/clock_getres.S
+++ b/arch/s390/kernel/vdso64/clock_getres.S
@@ -23,7 +23,9 @@ __kernel_clock_getres:
        je      0f
        cghi    %r2,__CLOCK_MONOTONIC
        je      0f
-       cghi    %r2,-2          /* CLOCK_THREAD_CPUTIME_ID for this thread */
+       cghi    %r2,__CLOCK_THREAD_CPUTIME_ID
+       je      0f
+       cghi    %r2,-2          /* Per-thread CPUCLOCK with PID=0, VIRT=1 */
        jne     2f
        larl    %r5,_vdso_data
        icm     %r0,15,__LC_ECTG_OK(%r5)

diff --git a/arch/s390/kernel/vdso64/clock_gettime.S b/arch/s390/kernel/vdso64/clock_gettime.S
index 0add107..4007007 100644 (file)
--- a/arch/s390/kernel/vdso64/clock_gettime.S
+++ b/arch/s390/kernel/vdso64/clock_gettime.S
@@ -22,7 +22,9 @@ __kernel_clock_gettime:
        larl    %r5,_vdso_data
        cghi    %r2,__CLOCK_REALTIME
        je      4f
-       cghi    %r2,-2          /* CLOCK_THREAD_CPUTIME_ID for this thread */
+       cghi    %r2,__CLOCK_THREAD_CPUTIME_ID
+       je      9f
+       cghi    %r2,-2          /* Per-thread CPUCLOCK with PID=0, VIRT=1 */
        je      9f
        cghi    %r2,__CLOCK_MONOTONIC
        jne     12f