From: Christopher Covington <cov@codeaurora.org>
To: Pawel Moll <pawel.moll@arm.com>
Cc: Richard Cochran <richardcochran@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Paul Mackerras <paulus@samba.org>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
John Stultz <john.stultz@linaro.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-api@vger.kernel.org" <linux-api@vger.kernel.org>
Subject: Re: [RFC 2/2] perf: Marker software event and ioctl
Date: Fri, 12 Sep 2014 10:00:09 -0400 [thread overview]
Message-ID: <5412FC69.8080709@codeaurora.org> (raw)
In-Reply-To: <1410526672.16936.52.camel@hornet>
On 09/12/2014 08:57 AM, Pawel Moll wrote:
> On Fri, 2014-09-12 at 13:43 +0100, Christopher Covington wrote:
>> Just to ask the dumb questions in case the answers I've come up with are
>> wrong: What is PAGE_SIZE on an arm64 kernel?
>
> It's either 4 or 64k, depending on CONFIG_ARM64_64K_PAGES.
>
>> How does userspace know?
>>
> #include <unistd.h>
> #include <stdio.h>
>
> int main(void)
> {
> printf("%ld\n", sysconf(_SC_PAGESIZE));
> return 0;
> }
Oh excellent, that actually works. Based on a misreading of the glibc code I
thought it was hard-coded to 64K.
Thanks,
Christopher
--
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by the Linux Foundation.
next prev parent reply other threads:[~2014-09-12 14:00 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-12 11:48 [RFC 0/2] Yet another take at user/kernel time correlation problem Pawel Moll
2014-09-12 11:48 ` [RFC 1/2] perf: Add sampling of the raw monotonic clock Pawel Moll
2014-09-12 11:48 ` [RFC 2/2] perf: Marker software event and ioctl Pawel Moll
2014-09-12 12:43 ` Christopher Covington
2014-09-12 12:57 ` Pawel Moll
2014-09-12 13:49 ` Arnaldo Carvalho de Melo
2014-09-12 13:58 ` Pawel Moll
2014-09-12 16:19 ` Arnaldo Carvalho de Melo
2014-09-15 17:27 ` Pawel Moll
2014-09-15 18:31 ` Arnaldo Carvalho de Melo
2014-09-16 16:33 ` Pawel Moll
2014-09-12 14:00 ` Christopher Covington [this message]
2014-09-12 17:37 ` David Ahern
2014-09-12 20:44 ` Arnaldo Carvalho de Melo
2014-09-14 15:43 ` David Ahern
2014-09-15 17:18 ` Pawel Moll
2014-09-16 7:44 ` Ingo Molnar
2014-09-16 16:37 ` Pawel Moll
2014-09-16 17:58 ` Ingo Molnar
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