From: Michael Neuling <mikey@neuling.org>
To: Cyril Bur <cyrilbur@gmail.com>, anton@samba.org, linuxppc-dev@ozlabs.org
Subject: Re: [PATCH 2/8] selftests/powerpc: Test preservation of FPU and VMX regs across preemption
Date: Mon, 23 Nov 2015 11:34:30 +1100 [thread overview]
Message-ID: <1448238870.3483.107.camel@neuling.org> (raw)
In-Reply-To: <1447817215-15804-3-git-send-email-cyrilbur@gmail.com>
On Wed, 2015-11-18 at 14:26 +1100, Cyril Bur wrote:
> Loop in assembly checking the registers with many threads.
>=20
> Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
> ---
> tools/testing/selftests/powerpc/math/Makefile | 7 +-
> tools/testing/selftests/powerpc/math/fpu_asm.S | 34 ++++++++
> tools/testing/selftests/powerpc/math/fpu_preempt.c | 92 ++++++++++++++++=
++++++
> tools/testing/selftests/powerpc/math/vmx_asm.S | 44 ++++++++++-
> tools/testing/selftests/powerpc/math/vmx_preempt.c | 92 ++++++++++++++++=
++++++
> 5 files changed, 263 insertions(+), 6 deletions(-)
> create mode 100644 tools/testing/selftests/powerpc/math/fpu_preempt.c
> create mode 100644 tools/testing/selftests/powerpc/math/vmx_preempt.c
>=20
> diff --git a/tools/testing/selftests/powerpc/math/Makefile
b/tools/testing/selftests/powerpc/math/Makefile
> index 896d9e2..9fa690f 100644
> --- a/tools/testing/selftests/powerpc/math/Makefile
> +++ b/tools/testing/selftests/powerpc/math/Makefile
> @@ -1,12 +1,15 @@
> -TEST_PROGS :=3D fpu_syscall vmx_syscall
> +TEST_PROGS :=3D fpu_syscall fpu_preempt vmx_syscall vmx_preempt
.gitignore for this new build object
> all: $(TEST_PROGS)
> =20
> $(TEST_PROGS): ../harness.c
> -$(TEST_PROGS): CFLAGS +=3D -O2 -g
> +$(TEST_PROGS): CFLAGS +=3D -O2 -g -pthread
> =20
> fpu_syscall: fpu_asm.S
> +fpu_preempt: fpu_asm.S
> +
> vmx_syscall: vmx_asm.S
> +vmx_preempt: vmx_asm.S
> =20
> include ../../lib.mk
> =20
> diff --git a/tools/testing/selftests/powerpc/math/fpu_asm.S b/tools/testi=
ng/selftests/powerpc/math/fpu_asm.S
> index d5412c1..5ff0adc 100644
> --- a/tools/testing/selftests/powerpc/math/fpu_asm.S
> +++ b/tools/testing/selftests/powerpc/math/fpu_asm.S
> @@ -149,3 +149,37 @@ FUNC_START(test_fpu)
> > > POP_BASIC_STACK(256)
> > > blr
> FUNC_END(test_fpu)
> +
> +#int preempt_fpu(double *darray, volatile int *not_ready, int *sentinal)
> +#On starting will (atomically) decrement not_ready as a signal that the =
FPU
> +#has been loaded with darray. Will proceed to check the validity of the =
FPU
> +#registers while sentinal is not zero.
> +FUNC_START(preempt_fpu)
> +> > PUSH_BASIC_STACK(256)
> +> > std r3,32(sp) #double *darray
> +> > std r4,40(sp) #volatile int *not_ready
> +> > std r5,48(sp) #int *sentinal
> +> > PUSH_FPU(56)
> +
> +> > bl load_fpu
> +
Memory barrier here.
> +> > #Atomic DEC
> +> > ld r3,40(sp)
> +1:> > lwarx r4,0,r3
> +> > addi r4,r4,-1
> +> > stwcx. r4,0,r3
> +> > bne- 1b
> +
> +2:> > ld r3, 32(sp)
> +> > bl check_fpu
> +> > cmpdi r3,0
> +> > bne 3f
> +> > ld r4, 48(sp)
> +> > ld r5, 0(r4)
> +> > cmpwi r5,0
> +> > bne 2b
> +
> +3:> > POP_FPU(56)
> +> > POP_BASIC_STACK(256)
> +> > blr
> +FUNC_END(preempt_fpu)
> diff --git a/tools/testing/selftests/powerpc/math/fpu_preempt.c b/tools/t=
esting/selftests/powerpc/math/fpu_preempt.c
> new file mode 100644
> index 0000000..e24cf9b
> --- /dev/null
> +++ b/tools/testing/selftests/powerpc/math/fpu_preempt.c
Needs a copyright and a description of the test here.
Same in patch 1.
> @@ -0,0 +1,92 @@
> +#include <stdio.h>
> +#include <unistd.h>
> +#include <sys/syscall.h>
> +#include <sys/time.h>
> +#include <sys/types.h>
> +#include <sys/wait.h>
> +#include <stdlib.h>
> +#include <pthread.h>
> +
> +#include "utils.h"
> +
> +/* Time to wait for workers to get preempted (seconds) */
> +#define PREEMPT_TIME 20
> +/*
> + * Factor by which to multiply number of online CPUs for total number of
> + * worker threads
> + */
> +#define THREAD_FACTOR 8
> +
> +
> +__thread double darray[] =3D {0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.=
9, 1.0,
> +> > > 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0,
> +> > > 2.1};
> +
> +volatile int not_ready;
> +int running;
> +
> +extern void preempt_fpu(double *darray, volatile int *not_ready, int *se=
ntinal);
> +
> +void *preempt_fpu_c(void *p)
> +{
> +> > int i;
> +> > srand(pthread_self());
> +> > for (i =3D 0; i < 21; i++)
> +> > > darray[i] =3D rand();
> +
> +> > /* Test failed if it ever returns */
> +> > preempt_fpu(darray, ¬_ready, &running);
> +
> +> > return p;
> +}
> +
> +int test_preempt_fpu(void)
> +{
> +> > int i, rc, threads;
> +> > pthread_t *tids;
> +
> +> > threads =3D sysconf(_SC_NPROCESSORS_ONLN) * THREAD_FACTOR;
> +> > tids =3D malloc((threads) * sizeof(pthread_t));
> +> > FAIL_IF(!tids);
> +
> +> > running =3D true;
> +> > not_ready =3D threads;
> +> > for (i =3D 0; i < threads; i++) {
> +> > > rc =3D pthread_create(&tids[i], NULL, preempt_fpu_c, NULL);
> +> > > FAIL_IF(rc);
> +> > }
> +
> +> > setbuf(stdout, NULL);
> +> > /* Not really nessesary but nice to wait for every thread to start =
*/
> +> > printf("\tWaiting for all workers to start...");
> +> > while(not_ready);
You need a memory barrier here and a matching one in the asm which is
derementing it. Same in the VSX test.
> +> > printf("done\n");
> +
> +> > printf("\tWaiting for %d seconds to let some workers get preempted.=
..", PREEMPT_TIME);
> +> > sleep(PREEMPT_TIME);
> +> > printf("done\n");
> +
> +> > printf("\tKilling workers...");
> +> > running =3D 0;
> +> > for (i =3D 0; i < threads; i++) {
> +> > > void *rc_p;
> +> > > pthread_join(tids[i], &rc_p);
> +
> +> > > /*
> +> > > * Harness will say the fail was here, look at why preempt_fpu
> +> > > * returned
> +> > > */
> +> > > if ((long) rc_p)
> +> > > > printf("oops\n");
> +> > > FAIL_IF((long) rc_p);
> +> > }
> +> > printf("done\n");
> +
> +> > free(tids);
> +> > return 0;
> +}
> +
> +int main(int argc, char *argv[])
> +{
> +> > return test_harness(test_preempt_fpu, "fpu_preempt");
> +}
> diff --git a/tools/testing/selftests/powerpc/math/vmx_asm.S b/tools/testi=
ng/selftests/powerpc/math/vmx_asm.S
> index e642e67..23db4b3 100644
> --- a/tools/testing/selftests/powerpc/math/vmx_asm.S
> +++ b/tools/testing/selftests/powerpc/math/vmx_asm.S
> @@ -1,5 +1,6 @@
> #include "basic_asm.h"
> =20
> +#POS MUST BE 16 ALIGNED!
> #define PUSH_VMX(pos,reg) \
> > > li> > reg,pos; \
> > > stvx> > v20,reg,sp; \
> @@ -26,6 +27,7 @@
> > > addi> > reg,reg,16; \
> > > stvx> > v31,reg,sp;
> =20
> +#POS MUST BE 16 ALIGNED!
> #define POP_VMX(pos,reg) \
> > > li> > reg,pos; \
> > > lvx> > v20,reg,sp; \
> @@ -84,7 +86,7 @@ FUNC_END(load_vmx)
> =20
> #Should be safe from C, only touches r4, r5 and v0,v1,v2
> FUNC_START(check_vmx)
> -> > PUSH_BASIC_STACK(16)
> +> > PUSH_BASIC_STACK(32)
> > > mr r4,r3
> > > li> > r3,1 #assume a bad result
> > > li> > r5,0
> @@ -153,7 +155,7 @@ FUNC_START(check_vmx)
> > > cmpdi> > r0,0xffffffff
> > > bne> > 1f
> > > li> > r3,0
> -1:> > POP_BASIC_STACK(16)
> +1:> > POP_BASIC_STACK(32)
> > > blr
> FUNC_END(check_vmx)
> =20
> @@ -164,7 +166,7 @@ FUNC_START(test_vmx)
> > > PUSH_BASIC_STACK(512)
> > > std> > r3,40(sp) #Address of varray
> > > std r4,48(sp) #address of pid
> -> > PUSH_VMX(56, r4)
> +> > PUSH_VMX(64, r4)
> =20
> > > bl load_vmx
> =20
> @@ -177,7 +179,41 @@ FUNC_START(test_vmx)
> > > ld r3,40(sp)
> > > bl check_vmx
> =20
> -> > POP_VMX(56,r4)
> +> > POP_VMX(64,r4)
> > > POP_BASIC_STACK(512)
> > > blr
> FUNC_END(test_vmx)
> +
> +#int preempt_vmx(v4si *varray, volatile int *not_ready, int *sentinal)
> +#On starting will (atomically) decrement not_ready as a signal that the =
FPU
> +#has been loaded with varray. Will proceed to check the validity of the =
FPU
> +#registers while sentinal is not zero.
> +FUNC_START(preempt_vmx)
> +> > PUSH_BASIC_STACK(512)
> +> > std r3,32(sp) #v4si *varray
> +> > std r4,40(sp) #volatile int *not_ready
> +> > std r5,48(sp) #int *sentinal
> +> > PUSH_VMX(64,r4)
> +
> +> > bl load_vmx
> +
Memory barrier here
> +> > #Atomic DEC
> +> > ld r3,40(sp)
> +1:> > lwarx r4,0,r3
> +> > addi r4,r4,-1
> +> > stwcx. r4,0,r3
> +> > bne- 1b
> +
> +2:> > ld r3,32(sp)
> +> > bl check_vmx
> +> > cmpdi r3,0
> +> > bne 3f
> +> > ld r4,48(sp)
> +> > ld r5,0(r4)
> +> > cmpwi r5,0
> +> > bne 2b
> +
> +3:> > POP_VMX(64,r4)
> +> > POP_BASIC_STACK(512)
> +> > blr
> +FUNC_END(preempt_vmx)
> diff --git a/tools/testing/selftests/powerpc/math/vmx_preempt.c b/tools/t=
esting/selftests/powerpc/math/vmx_preempt.c
> new file mode 100644
> index 0000000..342db15
> --- /dev/null
> +++ b/tools/testing/selftests/powerpc/math/vmx_preempt.c
Needs a copyright and a description of the test here. =20
> @@ -0,0 +1,92 @@
> +#include <stdio.h>
> +#include <unistd.h>
> +#include <sys/syscall.h>
> +#include <sys/time.h>
> +#include <sys/types.h>
> +#include <sys/wait.h>
> +#include <stdlib.h>
> +#include <pthread.h>
> +
> +#include "utils.h"
> +
> +/* Time to wait for workers to get preempted (seconds) */
> +#define PREEMPT_TIME 20
> +/*
> + * Factor by which to multiply number of online CPUs for total number of
> + * worker threads
> + */
> +#define THREAD_FACTOR 8
> +
> +typedef int v4si __attribute__ ((vector_size (16)));
> +__thread v4si varray[] =3D {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10,11,12},
> +> > {13,14,15,16},{17,18,19,20},{21,22,23,24},
> +> > {25,26,27,28},{29,30,31,32},{33,34,35,36},
> +> > {37,38,39,40},{41,42,43,44},{45,46,47,48}};
> +
> +volatile int not_ready;
I really hate this name. How about just "ready" and you negate the
code.
> +int running;
Now about not_running ;-P
> +
> +extern void preempt_vmx(v4si *varray, volatile int *not_ready, int *sent=
inal);
> +
> +void *preempt_vmx_c(void *p)
> +{
> +> > int i, j;
> +> > srand(pthread_self());
> +> > for (i =3D 0; i < 12; i++)
> +> > > for (j =3D 0; j < 4; j++)
> +> > > > varray[i][j] =3D rand();
> +
> +> > /* Test fails if it ever returns */
> +> > preempt_vmx(varray, ¬_ready, &running);
> +> > return p;
> +}
> +
> +int test_preempt_vmx(void)
> +{
> +> > int i, rc, threads;
> +> > pthread_t *tids;
> +
> +> > threads =3D sysconf(_SC_NPROCESSORS_ONLN) * THREAD_FACTOR;
> +> > tids =3D malloc(threads * sizeof(pthread_t));
> +> > FAIL_IF(!tids);
> +
> +> > running =3D true;
> +> > not_ready =3D threads;
> +> > for (i =3D 0; i < threads; i++) {
> +> > > rc =3D pthread_create(&tids[i], NULL, preempt_vmx_c, NULL);
> +> > > FAIL_IF(rc);
> +> > }
> +
> +> > setbuf(stdout, NULL);
> +> > /* Not really nessesary but nice to wait for every thread to start =
*/
> +> > printf("\tWaiting for all workers to start...");
> +> > while(not_ready);
Again, a memory barrier here.
> +> > printf("done\n");
> +
> +> > printf("\tWaiting for %d seconds to let some workers get preempted.=
..", PREEMPT_TIME);
> +> > sleep(PREEMPT_TIME);
> +> > printf("done\n");
> +
> +> > printf("\tKilling workers...");
> +> > running =3D 0;
> +> > for (i =3D 0; i < threads; i++) {
> +> > > void *rc_p;
> +> > > pthread_join(tids[i], &rc_p);
> +
> +> > > /*
> +> > > * Harness will say the fail was here, look at why preempt_vmx
> +> > > * returned
> +> > > */
> +> > > if ((long) rc_p)
> +> > > > printf("oops\n");
> +> > > FAIL_IF((long) rc_p);
> +> > }
> +> > printf("done\n");
> +
> +> > return 0;
> +}
> +
> +int main(int argc, char *argv[])
> +{
> +> > return test_harness(test_preempt_vmx, "vmx_preempt");
> +}
next prev parent reply other threads:[~2015-11-23 0:34 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-18 3:26 [PATCH 0/8] FP/VEC/VSX switching optimisations Cyril Bur
2015-11-18 3:26 ` [PATCH 1/8] selftests/powerpc: Test the preservation of FPU and VMX regs across syscall Cyril Bur
2015-11-23 0:23 ` Michael Neuling
2015-11-23 0:58 ` Cyril Bur
2015-11-23 1:06 ` Michael Neuling
2015-11-18 3:26 ` [PATCH 2/8] selftests/powerpc: Test preservation of FPU and VMX regs across preemption Cyril Bur
2015-11-23 0:34 ` Michael Neuling [this message]
2015-11-18 3:26 ` [PATCH 3/8] selftests/powerpc: Test FPU and VMX regs in signal ucontext Cyril Bur
2015-11-19 11:36 ` [3/8] " Michael Ellerman
2015-11-23 1:04 ` [PATCH 3/8] " Michael Neuling
2015-11-18 3:26 ` [PATCH 4/8] powerpc: Explicitly disable math features when copying thread Cyril Bur
2015-11-23 1:08 ` Michael Neuling
2015-11-23 3:20 ` Cyril Bur
2015-11-18 3:26 ` [PATCH 5/8] powerpc: Restore FPU/VEC/VSX if previously used Cyril Bur
2015-11-20 11:01 ` Michael Ellerman
2015-11-22 22:18 ` Cyril Bur
2015-11-22 23:07 ` Michael Ellerman
2015-11-23 1:29 ` Michael Neuling
2015-11-18 3:26 ` [PATCH 6/8] powerpc: Add the ability to save FPU without giving it up Cyril Bur
2015-11-18 3:26 ` [PATCH 7/8] powerpc: Add the ability to save Altivec " Cyril Bur
2015-11-18 3:26 ` [PATCH 8/8] powerpc: Add the ability to save VSX " Cyril Bur
2015-11-18 14:51 ` [PATCH 0/8] FP/VEC/VSX switching optimisations David Laight
2015-11-18 23:01 ` Cyril Bur
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