From: Arun Sharma <asharma@fb.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: <linux-kernel@vger.kernel.org>, Kumar Sundararajan <kumar@fb.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>,
john stultz <johnstul@us.ibm.com>, Andy Lutomirski <luto@MIT.EDU>
Subject: Re: [PATCH 2/2] Add a thread cpu time implementation to vDSO
Date: Mon, 12 Dec 2011 14:14:13 -0800 [thread overview]
Message-ID: <4EE67CB5.7000404@fb.com> (raw)
In-Reply-To: <1323725243.2583.27.camel@edumazet-laptop>
On 12/12/11 1:27 PM, Eric Dumazet wrote:
> This only works if CONFIG_X86_L1_CACHE_SHIFT=6
>
> Some configurations have 128 bytes cache lines
>
I could still handle this case based on compile time math.
> But really most modern distros have NR_CPUS> 64
Is 256 the new 64? :)
That'll require 3 more VVAR pages, most of which would be unused on the
vast majority of the systems (assuming 32 CPUs or less).
Having the number of VVAR pages configurable at boot time would solve
this problem nicely. I think that should be a separate patch.
-Arun
next prev parent reply other threads:[~2011-12-12 22:16 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-12 19:36 [PATCH 0/2] Add a thread cpu time implementation to vDSO Arun Sharma
2011-12-12 19:36 ` [PATCH 1/2] Extend VVAR support to multiple pages Arun Sharma
2011-12-12 19:36 ` [PATCH 2/2] Add a thread cpu time implementation to vDSO Arun Sharma
2011-12-12 20:13 ` Eric Dumazet
2011-12-12 21:19 ` Arun Sharma
2011-12-12 21:27 ` Eric Dumazet
2011-12-12 21:33 ` Andrew Lutomirski
2011-12-12 22:14 ` Arun Sharma [this message]
2011-12-13 8:52 ` Peter Zijlstra
2011-12-13 18:15 ` Arun Sharma
2011-12-13 18:53 ` Peter Zijlstra
2011-12-12 20:15 ` Andrew Lutomirski
2011-12-12 22:49 ` Arun Sharma
2011-12-12 23:01 ` Andrew Lutomirski
2011-12-13 0:40 ` Arun Sharma
2011-12-12 23:09 ` john stultz
2011-12-12 23:20 ` Arun Sharma
2011-12-12 23:32 ` john stultz
2011-12-12 23:41 ` Andrew Lutomirski
2011-12-12 23:52 ` john stultz
2011-12-13 0:26 ` Arun Sharma
-- strict thread matches above, loose matches on Subject: below --
2011-12-19 19:51 [PATCH 0/2] Add a thread cpu time implementation to vDSO (v2) Arun Sharma
2011-12-19 19:51 ` [PATCH 2/2] Add a thread cpu time implementation to vDSO Arun Sharma
2011-12-19 19:58 ` Arun Sharma
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