user/sven/linux.git, branch v2.6.35.4

Linux 2.6.35.4

2010-08-26T23:47:12Z

tracing: Fix timer tracing

2010-08-26T23:46:32Z

commit ede1b4290781ae82ccf0f2ecc6dada8d3dd35779 upstream. PowerTOP would like to be able to trace timers. Unfortunately, the current timer tracing is not very useful: the actual timer function is not recorded in the trace at the start of timer execution. Although this is recorded for timer "start" time (when it gets armed), this is not useful; most timers get started early, and a tracer like PowerTOP will never see this event, but will only see the actual running of the timer. This patch just adds the function to the timer tracing; I've verified with PowerTOP that now it can get useful information about timers. Signed-off-by: Arjan van de Ven Cc: xiaoguangrong@cn.fujitsu.com Cc: Steven Rostedt Cc: Frederic Weisbecker Cc: Peter Zijlstra LKML-Reference: <4C6C5FA9.3000405@linux.intel.com> Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

mutex: Improve the scalability of optimistic spinning

2010-08-26T23:46:32Z

commit 9d0f4dcc5c4d1c5dd01172172684a45b5f49d740 upstream. There is a scalability issue for current implementation of optimistic mutex spin in the kernel. It is found on a 8 node 64 core Nehalem-EX system (HT mode). The intention of the optimistic mutex spin is to busy wait and spin on a mutex if the owner of the mutex is running, in the hope that the mutex will be released soon and be acquired, without the thread trying to acquire mutex going to sleep. However, when we have a large number of threads, contending for the mutex, we could have the mutex grabbed by other thread, and then another ……, and we will keep spinning, wasting cpu cycles and adding to the contention. One possible fix is to quit spinning and put the current thread on wait-list if mutex lock switch to a new owner while we spin, indicating heavy contention (see the patch included). I did some testing on a 8 socket Nehalem-EX system with a total of 64 cores. Using Ingo's test-mutex program that creates/delete files with 256 threads (http://lkml.org/lkml/2006/1/8/50) , I see the following speed up after putting in the mutex spin fix: ./mutex-test V 256 10 Ops/sec 2.6.34 62864 With fix 197200 Repeating the test with Aim7 fserver workload, again there is a speed up with the fix: Jobs/min 2.6.34 91657 With fix 149325 To look at the impact on the distribution of mutex acquisition time, I collected the mutex acquisition time on Aim7 fserver workload with some instrumentation. The average acquisition time is reduced by 48% and number of contentions reduced by 32%. #contentions Time to acquire mutex (cycles) 2.6.34 72973 44765791 With fix 49210 23067129 The histogram of mutex acquisition time is listed below. The acquisition time is in 2^bin cycles. We see that without the fix, the acquisition time is mostly around 2^26 cycles. With the fix, we the distribution get spread out a lot more towards the lower cycles, starting from 2^13. However, there is an increase of the tail distribution with the fix at 2^28 and 2^29 cycles. It seems a small price to pay for the reduced average acquisition time and also getting the cpu to do useful work. Mutex acquisition time distribution (acq time = 2^bin cycles): 2.6.34 With Fix bin #occurrence % #occurrence % 11 2 0.00% 120 0.24% 12 10 0.01% 790 1.61% 13 14 0.02% 2058 4.18% 14 86 0.12% 3378 6.86% 15 393 0.54% 4831 9.82% 16 710 0.97% 4893 9.94% 17 815 1.12% 4667 9.48% 18 790 1.08% 5147 10.46% 19 580 0.80% 6250 12.70% 20 429 0.59% 6870 13.96% 21 311 0.43% 1809 3.68% 22 255 0.35% 2305 4.68% 23 317 0.44% 916 1.86% 24 610 0.84% 233 0.47% 25 3128 4.29% 95 0.19% 26 63902 87.69% 122 0.25% 27 619 0.85% 286 0.58% 28 0 0.00% 3536 7.19% 29 0 0.00% 903 1.83% 30 0 0.00% 0 0.00% I've done similar experiments with 2.6.35 kernel on smaller boxes as well. One is on a dual-socket Westmere box (12 cores total, with HT). Another experiment is on an old dual-socket Core 2 box (4 cores total, no HT) On the 12-core Westmere box, I see a 250% increase for Ingo's mutex-test program with my mutex patch but no significant difference in aim7's fserver workload. On the 4-core Core 2 box, I see the difference with the patch for both mutex-test and aim7 fserver are negligible. So far, it seems like the patch has not caused regression on smaller systems. Signed-off-by: Tim Chen Acked-by: Peter Zijlstra Cc: Linus Torvalds Cc: Andrew Morton Cc: Thomas Gleixner Cc: Frederic Weisbecker LKML-Reference: <1282168827.9542.72.camel@schen9-DESK> Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

USB: ftdi_sio: add product ID for Lenz LI-USB

2010-08-26T23:46:32Z

commit ea233f805537f5da16c2b34d85b6c5cf88a0f9aa upstream. Add ftdi product ID for Lenz LI-USB, a model train interface. This was NOT tested against 2.6.35, but a similar patch was tested with the CentOS 2.6.18-194.11.1.el5 kernel. It wasn't clear to me what ordering is being used in ftdi_sio.c, so I inserted the ID after another model train entry(SPROG_II). Signed-off-by: Galen Seitz Signed-off-by: Greg Kroah-Hartman

USB: ftdi_sio: Add ID for Ionics PlugComputer

2010-08-26T23:46:32Z

commit 666cc076d284e32d11bfc5ea2fbfc50434cff051 upstream. Add the ID for the Ionics PlugComputer (). Signed-off-by: Martin Michlmayr Signed-off-by: Greg Kroah-Hartman

USB: xhci: Remove buggy assignment in next_trb()

2010-08-26T23:46:25Z

commit a1669b2c64a9c8b031e0ac5cbf2692337a577f7c upstream. The code to increment the TRB pointer has a slight ambiguity that could lead to a bug on different compilers. The ANSI C specification does not specify the precedence of the assignment operator over the postfix operator. gcc 4.4 produced the correct code (increment the pointer and assign the value), but a MIPS compiler that one of John's clients used assigned the old (unincremented) value. Remove the unnecessary assignment to make all compilers produce the correct assembly. Signed-off-by: John Youn Signed-off-by: Sarah Sharp Signed-off-by: Greg Kroah-Hartman

USB: io_ti: check firmware version before updating

2010-08-26T23:46:24Z

commit 0827a9ff2bbcbb03c33f1a6eb283fe051059482c upstream. If we can't read the firmware for a device from the disk, and yet the device already has a valid firmware image in it, we don't want to replace the firmware with something invalid. So check the version number to be less than the current one to verify this is the correct thing to do. Reported-by: Chris Beauchamp Tested-by: Chris Beauchamp Cc: Alan Stern Signed-off-by: Greg Kroah-Hartman

USB: ftdi_sio: fix endianess of max packet size

2010-08-26T23:46:24Z

commit d1ab903d2552b2362339b19203c7f01c797cb316 upstream. The USB max packet size (always little-endian) was not being byte swapped on big-endian systems. Applicable since [USB: ftdi_sio: fix hi-speed device packet size calculation] approx 2.6.31 Signed-off-by: Michael Wileczka Signed-off-by: Greg Kroah-Hartman

USB: CP210x Fix Break On/Off

2010-08-26T23:46:24Z

commit 72916791cbeb9cc607ae620cfba207dea481cd76 upstream. The definitions for BREAK_ON and BREAK_OFF are inverted, causing break requests to fail. This patch sets BREAK_ON and BREAK_OFF to the correct values. Signed-off-by: Craig Shelley Signed-off-by: Greg Kroah-Hartman

USB: pl2303: New vendor and product id

2010-08-26T23:46:24Z

commit f36ecd5de93e4c85a9e3d25100c6e233155b12e5 upstream. Add support for the Zeagle N2iTiON3 dive computer interface. Since Zeagle devices are actually manufactured by Seiko, this patch will support other Seiko based models as well. Signed-off-by: Jef Driesen Signed-off-by: Greg Kroah-Hartman