From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx197.postini.com [74.125.245.197]) by kanga.kvack.org (Postfix) with SMTP id 576E76B007B for ; Tue, 20 Nov 2012 02:44:52 -0500 (EST) Received: by mail-ee0-f41.google.com with SMTP id d41so4046919eek.14 for ; Mon, 19 Nov 2012 23:44:50 -0800 (PST) Date: Tue, 20 Nov 2012 08:44:45 +0100 From: Ingo Molnar Subject: Re: [PATCH 00/27] Latest numa/core release, v16 Message-ID: <20121120074445.GA14539@gmail.com> References: <1353291284-2998-1-git-send-email-mingo@kernel.org> <20121119162909.GL8218@suse.de> <20121120060014.GA14065@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: David Rientjes Cc: Mel Gorman , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Peter Zijlstra , Paul Turner , Lee Schermerhorn , Christoph Lameter , Rik van Riel , Andrew Morton , Andrea Arcangeli , Linus Torvalds , Thomas Gleixner , Johannes Weiner , Hugh Dickins * David Rientjes wrote: > On Tue, 20 Nov 2012, Ingo Molnar wrote: > > > > > numa/core at ec05a2311c35 ("Merge branch 'sched/urgent' into > > > > sched/core") had an average throughput of 136918.34 > > > > SPECjbb2005 bops, which is a 6.3% regression. > > > > > > perftop during the run on numa/core at 01aa90068b12 ("sched: > > > Use the best-buddy 'ideal cpu' in balancing decisions"): > > > > > > 15.99% [kernel] [k] page_fault > > > 4.05% [kernel] [k] getnstimeofday > > > 3.96% [kernel] [k] _raw_spin_lock > > > 3.20% [kernel] [k] rcu_check_callbacks > > > 2.93% [kernel] [k] generic_smp_call_function_interrupt > > > 2.90% [kernel] [k] __do_page_fault > > > 2.82% [kernel] [k] ktime_get > > > > Thanks for testing, that's very interesting - could you tell me > > more about exactly what kind of hardware this is? I'll try to > > find a similar system and reproduce the performance regression. > > > > This happened to be an Opteron (but not 83xx series), 2.4Ghz. Ok - roughly which family/model from /proc/cpuinfo? > Your benchmarks were different in the number of cores but also > in the amount of memory, do you think numa/core would regress > because this is 32GB and not 64GB? I'd not expect much sensitivity to RAM size. > > (A wild guess would be an older 4x Opteron system, 83xx > > series or so?) > > Just curious, how you would guess that? [...] I'm testing numa/core on many systems and the performance figures seemed to roughly map to that range. > [...] Is there something about Opteron 83xx that make > numa/core regress? Not that I knew of - but apparently there is! I'll try to find a system that matches yours as closely as possible and have a look. > > Also, the profile looks weird to me. Here is how perf top looks > > like on my system during a similarly configured, "healthy" > > SPECjbb run: > > > > 91.29% perf-6687.map [.] 0x00007fffed1e8f21 > > 4.81% libjvm.so [.] 0x00000000007004a0 > > 0.93% [vdso] [.] 0x00007ffff7ffe60c > > 0.72% [kernel] [k] do_raw_spin_lock > > 0.36% [kernel] [k] generic_smp_call_function_interrupt > > 0.10% [kernel] [k] format_decode > > 0.07% [kernel] [k] rcu_check_callbacks > > 0.07% [kernel] [k] apic_timer_interrupt > > 0.07% [kernel] [k] call_function_interrupt > > 0.06% libc-2.15.so [.] __strcmp_sse42 > > 0.06% [kernel] [k] irqtime_account_irq > > 0.06% perf [.] 0x000000000004bb7c > > 0.05% [kernel] [k] x86_pmu_disable_all > > 0.04% libc-2.15.so [.] __memcpy_ssse3 > > 0.04% [kernel] [k] ktime_get > > 0.04% [kernel] [k] account_group_user_time > > 0.03% [kernel] [k] vbin_printf > > > > and that is what SPECjbb does: it spends 97% of its time in Java > > code - yet there's no Java overhead visible in your profile - > > how is that possible? Could you try a newer perf on that box: > > > > It's perf top -U, the benchmark itself was unchanged so I > didn't think it was interesting to gather the user symbols. > If that would be helpful, let me know! Yeah, regular perf top output would be very helpful to get a general sense of proportion. Thanks! Ingo -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org