From: "Sverdlin, Alexander (Nokia - DE/Ulm)" <alexander.sverdlin@nokia.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: "x86@kernel.org" <x86@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
"H. Peter Anvin" <hpa@zytor.com>,
Jason Vas Dias <jason.vas.dias@gmail.com>,
Andy Lutomirski <luto@kernel.org>,
Vincenzo Frascino <vincenzo.frascino@arm.com>
Subject: Re: [PATCH v3 1/2] x86/vdso: Move mult and shift into struct vgtod_ts
Date: Thu, 27 Jun 2019 12:00:48 +0000 [thread overview]
Message-ID: <01ab4388-f259-e801-8c8a-f39b5abcfb52@nokia.com> (raw)
In-Reply-To: <alpine.DEB.2.21.1906241135450.32342@nanos.tec.linutronix.de>
Hello Thomas!
On 24/06/2019 11:40, Thomas Gleixner wrote:
>>> The alternative solution for this is what Vincenzo has in his unified VDSO
>>> patch series:
>>>
>>> https://lkml.kernel.org/r/20190621095252.32307-1-vincenzo.frascino@arm.com
>>>
>>> It leaves the data struct unmodified and has a separate array for the raw
>>> clock. That does not have the side effects at all.
>>>
>>> I'm in the process of merging that series and I actually adapted your
>>> scheme to the new unified infrastructure where it has exactly the same
>>> effects as with your original patches against the x86 version.
>> please let me know if I need to rework [2/2] based on some not-yet-published
>> branch of yours.
> I've pushed it out now to
>
> git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers/vdso
>
> The generic VDSO library has the support for RAW already with that separate
> array. Testing would be welcomed!
Thanks for your and Vincenzo's efforts!
I've applied the series onto 5.2.0-rc6 and did a quick test on a bare x86_64 and
for me it looks good:
Number of clock_gettime() calls in 10 seconds:
Before After Diff
MONOTONIC 152404300 200825950 +32%
MONOTONIC_RAW 38804788 198765053 +412%
REALTIME 151672619 201371468 +33%
--
Best regards,
Alexander Sverdlin.
next prev parent reply other threads:[~2019-06-27 12:00 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-28 8:01 [PATCH] x86/vdso: implement clock_gettime(CLOCK_MONOTONIC_RAW, ...) Sverdlin, Alexander (Nokia - DE/Ulm)
2019-05-28 18:01 ` Thomas Gleixner
2019-06-04 16:42 ` [PATCH v2] " Sverdlin, Alexander (Nokia - DE/Ulm)
2019-06-04 17:39 ` Andy Lutomirski
2019-06-05 14:41 ` [PATCH v3 0/2] x86/vdso: CLOCK_MONOTONIC_RAW implementation Sverdlin, Alexander (Nokia - DE/Ulm)
2019-06-05 14:41 ` [PATCH v3 1/2] x86/vdso: Move mult and shift into struct vgtod_ts Sverdlin, Alexander (Nokia - DE/Ulm)
2019-06-23 10:18 ` Thomas Gleixner
2019-06-24 9:16 ` Sverdlin, Alexander (Nokia - DE/Ulm)
2019-06-24 9:40 ` Thomas Gleixner
2019-06-27 12:00 ` Sverdlin, Alexander (Nokia - DE/Ulm) [this message]
2019-06-27 12:07 ` Thomas Gleixner
2019-06-27 12:15 ` Sverdlin, Alexander (Nokia - DE/Ulm)
2019-06-27 12:21 ` Thomas Gleixner
2019-06-05 14:41 ` [PATCH v3 2/2] x86/vdso: implement clock_gettime(CLOCK_MONOTONIC_RAW, ...) Sverdlin, Alexander (Nokia - DE/Ulm)
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