From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Nathan Lynch <nathanl@linux.ibm.com>,
linux-arch <linux-arch@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Paul Mackerras <paulus@samba.org>,
Andy Lutomirski <luto@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Subject: Re: [PATCH v8 8/8] powerpc/vdso: Provide __kernel_clock_gettime64() on vdso32
Date: Sat, 9 May 2020 20:48:42 +0200 [thread overview]
Message-ID: <35e09925-b475-237c-57f2-3f10cf5ad9b2@csgroup.eu> (raw)
In-Reply-To: <d3f303f1-8b2c-0c54-5380-0b9a370a4eb3@csgroup.eu>
Le 09/05/2020 à 17:54, Christophe Leroy a écrit :
>
>
> Le 28/04/2020 à 18:05, Arnd Bergmann a écrit :
>> On Tue, Apr 28, 2020 at 3:16 PM Christophe Leroy
>> <christophe.leroy@c-s.fr> wrote:
>>>
>>> Provides __kernel_clock_gettime64() on vdso32. This is the
>>> 64 bits version of __kernel_clock_gettime() which is
>>> y2038 compliant.
>>>
>>> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
>>
>> Looks good to me
>>
>> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
>>
>> There was a bug on ARM for the corresponding function, so far it is
>> unclear
>> if this was a problem related to particular hardware, the 32-bit
>> kernel code,
>> or the common implementation of clock_gettime64 in the vdso library,
>> see https://github.com/richfelker/musl-cross-make/issues/96
>>
>> Just to be sure that powerpc is not affected by the same issue, can you
>> confirm that repeatedly calling clock_gettime64 on powerpc32, alternating
>> between vdso and syscall, results in monotically increasing times?
>>
>
> I think that's one of the things vdsotest checks, so yes that's ok I think.
>
Here is the full result with vdsotest:
gettimeofday: syscall: 3715 nsec/call
gettimeofday: libc: 794 nsec/call
gettimeofday: vdso: 947 nsec/call
getcpu: syscall: 1614 nsec/call
getcpu: libc: 484 nsec/call
getcpu: vdso: 184 nsec/call
clock-gettime64-realtime-coarse: syscall: 3152 nsec/call
clock-gettime64-realtime-coarse: libc: not tested
clock-gettime64-realtime-coarse: vdso: 653 nsec/call
clock-getres-realtime-coarse: syscall: 2963 nsec/call
clock-getres-realtime-coarse: libc: 745 nsec/call
clock-getres-realtime-coarse: vdso: 553 nsec/call
clock-gettime-realtime-coarse: syscall: 5120 nsec/call
clock-gettime-realtime-coarse: libc: 731 nsec/call
clock-gettime-realtime-coarse: vdso: 577 nsec/call
clock-gettime64-realtime: syscall: 3719 nsec/call
clock-gettime64-realtime: libc: not tested
clock-gettime64-realtime: vdso: 976 nsec/call
clock-getres-realtime: syscall: 2496 nsec/call
clock-getres-realtime: libc: 745 nsec/call
clock-getres-realtime: vdso: 546 nsec/call
clock-gettime-realtime: syscall: 4800 nsec/call
clock-gettime-realtime: libc: 1080 nsec/call
clock-gettime-realtime: vdso: 1798 nsec/call
clock-gettime64-boottime: syscall: 4132 nsec/call
clock-gettime64-boottime: libc: not tested
clock-gettime64-boottime: vdso: 975 nsec/call
clock-getres-boottime: syscall: 2497 nsec/call
clock-getres-boottime: libc: 730 nsec/call
clock-getres-boottime: vdso: 546 nsec/call
clock-gettime-boottime: syscall: 3728 nsec/call
clock-gettime-boottime: libc: 1079 nsec/call
clock-gettime-boottime: vdso: 941 nsec/call
clock-gettime64-tai: syscall: 4148 nsec/call
clock-gettime64-tai: libc: not tested
clock-gettime64-tai: vdso: 955 nsec/call
clock-getres-tai: syscall: 2494 nsec/call
clock-getres-tai: libc: 730 nsec/call
clock-getres-tai: vdso: 545 nsec/call
clock-gettime-tai: syscall: 3729 nsec/call
clock-gettime-tai: libc: 1079 nsec/call
clock-gettime-tai: vdso: 927 nsec/call
clock-gettime64-monotonic-raw: syscall: 3677 nsec/call
clock-gettime64-monotonic-raw: libc: not tested
clock-gettime64-monotonic-raw: vdso: 1032 nsec/call
clock-getres-monotonic-raw: syscall: 2494 nsec/call
clock-getres-monotonic-raw: libc: 745 nsec/call
clock-getres-monotonic-raw: vdso: 545 nsec/call
clock-gettime-monotonic-raw: syscall: 3276 nsec/call
clock-gettime-monotonic-raw: libc: 1140 nsec/call
clock-gettime-monotonic-raw: vdso: 1002 nsec/call
clock-gettime64-monotonic-coarse: syscall: 4099 nsec/call
clock-gettime64-monotonic-coarse: libc: not tested
clock-gettime64-monotonic-coarse: vdso: 653 nsec/call
clock-getres-monotonic-coarse: syscall: 2962 nsec/call
clock-getres-monotonic-coarse: libc: 745 nsec/call
clock-getres-monotonic-coarse: vdso: 545 nsec/call
clock-gettime-monotonic-coarse: syscall: 4297 nsec/call
clock-gettime-monotonic-coarse: libc: 730 nsec/call
clock-gettime-monotonic-coarse: vdso: 592 nsec/call
clock-gettime64-monotonic: syscall: 3863 nsec/call
clock-gettime64-monotonic: libc: not tested
clock-gettime64-monotonic: vdso: 975 nsec/call
clock-getres-monotonic: syscall: 2494 nsec/call
clock-getres-monotonic: libc: 745 nsec/call
clock-getres-monotonic: vdso: 545 nsec/call
clock-gettime-monotonic: syscall: 3465 nsec/call
clock-gettime-monotonic: libc: 1079 nsec/call
clock-gettime-monotonic: vdso: 927 nsec/call
Christophe
next prev parent reply other threads:[~2020-05-09 18:48 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-28 13:16 [PATCH v8 0/8] powerpc: switch VDSO to C implementation Christophe Leroy
2020-04-28 13:16 ` Christophe Leroy
2020-04-28 13:16 ` [PATCH v8 1/8] powerpc/vdso64: Switch from __get_datapage() to get_datapage inline macro Christophe Leroy
2020-04-28 13:16 ` Christophe Leroy
2020-04-28 13:16 ` [PATCH v8 2/8] powerpc/vdso: Remove __kernel_datapage_offset and simplify __get_datapage() Christophe Leroy
2020-04-28 13:16 ` Christophe Leroy
2020-07-16 2:59 ` Michael Ellerman
2020-08-04 11:17 ` Christophe Leroy
2020-08-04 11:17 ` Christophe Leroy
2020-08-25 14:15 ` Christophe Leroy
2020-08-26 13:58 ` Michael Ellerman
2020-08-27 20:34 ` Dmitry Safonov
2020-08-28 2:14 ` Michael Ellerman
2020-09-21 11:26 ` Will Deacon
2020-09-27 7:43 ` Christophe Leroy
2020-09-28 15:08 ` Dmitry Safonov
2020-10-23 11:22 ` Christophe Leroy
2020-10-23 11:25 ` Will Deacon
2020-10-23 11:57 ` Christophe Leroy
2020-10-23 13:29 ` Dmitry Safonov
2020-04-28 13:16 ` [PATCH v8 3/8] powerpc/vdso: Remove unused \tmp param in __get_datapage() Christophe Leroy
2020-04-28 13:16 ` [PATCH v8 4/8] powerpc/processor: Move cpu_relax() into asm/vdso/processor.h Christophe Leroy
2020-04-28 13:16 ` [PATCH v8 5/8] powerpc/vdso: Prepare for switching VDSO to generic C implementation Christophe Leroy
2020-04-28 13:16 ` Christophe Leroy
2020-07-15 1:04 ` Michael Ellerman
2020-07-15 1:04 ` Michael Ellerman
2020-07-15 18:47 ` Christophe Leroy
2020-07-16 23:18 ` Tulio Magno Quites Machado Filho
2020-08-04 11:14 ` Christophe Leroy
2020-08-04 11:14 ` Christophe Leroy
2020-08-05 6:24 ` Michael Ellerman
2020-08-05 13:35 ` Segher Boessenkool
2020-08-05 13:35 ` Segher Boessenkool
2020-08-06 2:03 ` Michael Ellerman
2020-08-06 18:33 ` Segher Boessenkool
2020-08-06 18:33 ` Segher Boessenkool
2020-08-07 2:44 ` Michael Ellerman
2020-04-28 13:16 ` [PATCH v8 6/8] powerpc/vdso: Switch " Christophe Leroy
2020-04-28 13:16 ` Christophe Leroy
2020-04-28 13:16 ` [PATCH v8 7/8] lib/vdso: force inlining of __cvdso_clock_gettime_common() Christophe Leroy
2020-04-28 13:16 ` Christophe Leroy
2020-04-28 13:16 ` [PATCH v8 8/8] powerpc/vdso: Provide __kernel_clock_gettime64() on vdso32 Christophe Leroy
2020-04-28 16:05 ` Arnd Bergmann
2020-05-09 15:54 ` Christophe Leroy
2020-05-09 18:48 ` Christophe Leroy [this message]
2020-05-29 18:56 ` [PATCH v8 0/8] powerpc: switch VDSO to C implementation Christophe Leroy
2020-06-03 10:04 ` Michael Ellerman
2020-07-16 12:55 ` Michael Ellerman
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