From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
To: Hauke Mehrtens <hauke@hauke-m.de>,
linux-mips@linux-mips.org, ralf@linux-mips.org
Cc: alex.smith@imgtec.com, "# v4 . 4+" <stable@vger.kernel.org>
Subject: Re: [PATCH] MIPS: vdso: flush the vdso data page to update it on all processes
Date: Sun, 21 Feb 2016 16:18:59 +0300 [thread overview]
Message-ID: <56C9B943.1080006@cogentembedded.com> (raw)
In-Reply-To: <1456059443-13889-1-git-send-email-hauke@hauke-m.de>
Hello.
On 2/21/2016 3:57 PM, Hauke Mehrtens wrote:
> Without flushing the vdso data page the vdso call is working on dated
> or unsynced data. This resulted in problems where the clock_gettime
> vdso call returned a time 6 seconds later after a 3 sounds sleep,
> while the syscall reported a time 3 sounds later like expected. This
s/sounds/seconds/ perhaps?
> happened very often and I got these ping results for example:
>
> root@OpenWrt:/# ping 192.168.1.255
> PING 192.168.1.255 (192.168.1.255): 56 data bytes
> 64 bytes from 192.168.1.3: seq=0 ttl=64 time=0.688 ms
> 64 bytes from 192.168.1.3: seq=1 ttl=64 time=4294172.045 ms
> 64 bytes from 192.168.1.3: seq=2 ttl=64 time=4293968.105 ms
> 64 bytes from 192.168.1.3: seq=3 ttl=64 time=4294055.920 ms
> 64 bytes from 192.168.1.3: seq=4 ttl=64 time=4294671.913 ms
>
> The flush is now done like it is done on the arm architecture code.
>
> This was tested on a Lantiq/Intel VRX288 (MIPS BE 34Kc V5.6 CPU with
> two VPEs)
>
> Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
> Cc: <stable@vger.kernel.org> # v4.4+
[...]
MBR, Sergei
prev parent reply other threads:[~2016-02-21 19:02 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-21 12:57 [PATCH] MIPS: vdso: flush the vdso data page to update it on all processes Hauke Mehrtens
2016-02-21 13:18 ` Sergei Shtylyov [this message]
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