From 5e9fd733fa34b491e7ac41c91aa42ba0a9d8ea10 Mon Sep 17 00:00:00 2001 From: Jon Mason Date: Sat, 4 Jul 2015 14:48:33 -0400 Subject: NTB: Add list to MAINTAINERS Add the new NTB mailing list to MAINTAINERS Signed-off-by: Jon Mason --- MAINTAINERS | 2 ++ 1 file changed, 2 insertions(+) (limited to 'MAINTAINERS') diff --git a/MAINTAINERS b/MAINTAINERS index b60e2b2369d2..754bc7332bcf 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -7258,6 +7258,7 @@ NTB DRIVER CORE M: Jon Mason M: Dave Jiang M: Allen Hubbe +L: linux-ntb@googlegroups.com S: Supported W: https://github.com/jonmason/ntb/wiki T: git git://github.com/jonmason/ntb.git @@ -7269,6 +7270,7 @@ F: include/linux/ntb_transport.h NTB INTEL DRIVER M: Jon Mason M: Dave Jiang +L: linux-ntb@googlegroups.com S: Supported W: https://github.com/jonmason/ntb/wiki T: git git://github.com/jonmason/ntb.git -- cgit v1.2.3 From 5b25b13ab08f616efd566347d809b4ece54570d1 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Fri, 11 Sep 2015 13:07:39 -0700 Subject: sys_membarrier(): system-wide memory barrier (generic, x86) Here is an implementation of a new system call, sys_membarrier(), which executes a memory barrier on all threads running on the system. It is implemented by calling synchronize_sched(). It can be used to distribute the cost of user-space memory barriers asymmetrically by transforming pairs of memory barriers into pairs consisting of sys_membarrier() and a compiler barrier. For synchronization primitives that distinguish between read-side and write-side (e.g. userspace RCU [1], rwlocks), the read-side can be accelerated significantly by moving the bulk of the memory barrier overhead to the write-side. The existing applications of which I am aware that would be improved by this system call are as follows: * Through Userspace RCU library (http://urcu.so) - DNS server (Knot DNS) https://www.knot-dns.cz/ - Network sniffer (http://netsniff-ng.org/) - Distributed object storage (https://sheepdog.github.io/sheepdog/) - User-space tracing (http://lttng.org) - Network storage system (https://www.gluster.org/) - Virtual routers (https://events.linuxfoundation.org/sites/events/files/slides/DPDK_RCU_0MQ.pdf) - Financial software (https://lkml.org/lkml/2015/3/23/189) Those projects use RCU in userspace to increase read-side speed and scalability compared to locking. Especially in the case of RCU used by libraries, sys_membarrier can speed up the read-side by moving the bulk of the memory barrier cost to synchronize_rcu(). * Direct users of sys_membarrier - core dotnet garbage collector (https://github.com/dotnet/coreclr/issues/198) Microsoft core dotnet GC developers are planning to use the mprotect() side-effect of issuing memory barriers through IPIs as a way to implement Windows FlushProcessWriteBuffers() on Linux. They are referring to sys_membarrier in their github thread, specifically stating that sys_membarrier() is what they are looking for. To explain the benefit of this scheme, let's introduce two example threads: Thread A (non-frequent, e.g. executing liburcu synchronize_rcu()) Thread B (frequent, e.g. executing liburcu rcu_read_lock()/rcu_read_unlock()) In a scheme where all smp_mb() in thread A are ordering memory accesses with respect to smp_mb() present in Thread B, we can change each smp_mb() within Thread A into calls to sys_membarrier() and each smp_mb() within Thread B into compiler barriers "barrier()". Before the change, we had, for each smp_mb() pairs: Thread A Thread B previous mem accesses previous mem accesses smp_mb() smp_mb() following mem accesses following mem accesses After the change, these pairs become: Thread A Thread B prev mem accesses prev mem accesses sys_membarrier() barrier() follow mem accesses follow mem accesses As we can see, there are two possible scenarios: either Thread B memory accesses do not happen concurrently with Thread A accesses (1), or they do (2). 1) Non-concurrent Thread A vs Thread B accesses: Thread A Thread B prev mem accesses sys_membarrier() follow mem accesses prev mem accesses barrier() follow mem accesses In this case, thread B accesses will be weakly ordered. This is OK, because at that point, thread A is not particularly interested in ordering them with respect to its own accesses. 2) Concurrent Thread A vs Thread B accesses Thread A Thread B prev mem accesses prev mem accesses sys_membarrier() barrier() follow mem accesses follow mem accesses In this case, thread B accesses, which are ensured to be in program order thanks to the compiler barrier, will be "upgraded" to full smp_mb() by synchronize_sched(). * Benchmarks On Intel Xeon E5405 (8 cores) (one thread is calling sys_membarrier, the other 7 threads are busy looping) 1000 non-expedited sys_membarrier calls in 33s =3D 33 milliseconds/call. * User-space user of this system call: Userspace RCU library Both the signal-based and the sys_membarrier userspace RCU schemes permit us to remove the memory barrier from the userspace RCU rcu_read_lock() and rcu_read_unlock() primitives, thus significantly accelerating them. These memory barriers are replaced by compiler barriers on the read-side, and all matching memory barriers on the write-side are turned into an invocation of a memory barrier on all active threads in the process. By letting the kernel perform this synchronization rather than dumbly sending a signal to every process threads (as we currently do), we diminish the number of unnecessary wake ups and only issue the memory barriers on active threads. Non-running threads do not need to execute such barrier anyway, because these are implied by the scheduler context switches. Results in liburcu: Operations in 10s, 6 readers, 2 writers: memory barriers in reader: 1701557485 reads, 2202847 writes signal-based scheme: 9830061167 reads, 6700 writes sys_membarrier: 9952759104 reads, 425 writes sys_membarrier (dyn. check): 7970328887 reads, 425 writes The dynamic sys_membarrier availability check adds some overhead to the read-side compared to the signal-based scheme, but besides that, sys_membarrier slightly outperforms the signal-based scheme. However, this non-expedited sys_membarrier implementation has a much slower grace period than signal and memory barrier schemes. Besides diminishing the number of wake-ups, one major advantage of the membarrier system call over the signal-based scheme is that it does not need to reserve a signal. This plays much more nicely with libraries, and with processes injected into for tracing purposes, for which we cannot expect that signals will be unused by the application. An expedited version of this system call can be added later on to speed up the grace period. Its implementation will likely depend on reading the cpu_curr()->mm without holding each CPU's rq lock. This patch adds the system call to x86 and to asm-generic. [1] http://urcu.so membarrier(2) man page: MEMBARRIER(2) Linux Programmer's Manual MEMBARRIER(2) NAME membarrier - issue memory barriers on a set of threads SYNOPSIS #include int membarrier(int cmd, int flags); DESCRIPTION The cmd argument is one of the following: MEMBARRIER_CMD_QUERY Query the set of supported commands. It returns a bitmask of supported commands. MEMBARRIER_CMD_SHARED Execute a memory barrier on all threads running on the system. Upon return from system call, the caller thread is ensured that all running threads have passed through a state where all memory accesses to user-space addresses match program order between entry to and return from the system call (non-running threads are de facto in such a state). This covers threads from all pro=E2=80=90 cesses running on the system. This command returns 0. The flags argument needs to be 0. For future extensions. All memory accesses performed in program order from each targeted thread is guaranteed to be ordered with respect to sys_membarrier(). If we use the semantic "barrier()" to represent a compiler barrier forcing memory accesses to be performed in program order across the barrier, and smp_mb() to represent explicit memory barriers forcing full memory ordering across the barrier, we have the following ordering table for each pair of barrier(), sys_membarrier() and smp_mb(): The pair ordering is detailed as (O: ordered, X: not ordered): barrier() smp_mb() sys_membarrier() barrier() X X O smp_mb() X O O sys_membarrier() O O O RETURN VALUE On success, these system calls return zero. On error, -1 is returned, and errno is set appropriately. For a given command, with flags argument set to 0, this system call is guaranteed to always return the same value until reboot. ERRORS ENOSYS System call is not implemented. EINVAL Invalid arguments. Linux 2015-04-15 MEMBARRIER(2) Signed-off-by: Mathieu Desnoyers Reviewed-by: Paul E. McKenney Reviewed-by: Josh Triplett Cc: KOSAKI Motohiro Cc: Steven Rostedt Cc: Nicholas Miell Cc: Ingo Molnar Cc: Alan Cox Cc: Lai Jiangshan Cc: Stephen Hemminger Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: David Howells Cc: Pranith Kumar Cc: Michael Kerrisk Cc: Shuah Khan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- MAINTAINERS | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'MAINTAINERS') diff --git a/MAINTAINERS b/MAINTAINERS index 310da4295c70..e77bc84dc580 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -6789,6 +6789,14 @@ W: http://www.mellanox.com Q: http://patchwork.ozlabs.org/project/netdev/list/ F: drivers/net/ethernet/mellanox/mlxsw/ +MEMBARRIER SUPPORT +M: Mathieu Desnoyers +M: "Paul E. McKenney" +L: linux-kernel@vger.kernel.org +S: Supported +F: kernel/membarrier.c +F: include/uapi/linux/membarrier.h + MEMORY MANAGEMENT L: linux-mm@kvack.org W: http://www.linux-mm.org -- cgit v1.2.3 From 64e05d8bcc837bc66cb2c6e71796c8883aa45939 Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Thu, 27 Aug 2015 07:32:11 +0530 Subject: thermal: cpu_cooling: Add MAINTAINERS entry None of the patches are reaching Viresh or Daniel directly as get_maintainers doesn't report us as maintainers. Looks like file header or history of commits isn't able to do that properly. Add a separate entry for cpu_cooling driver in MAINTAINERS. Acked-by: Eduardo Valentin Acked-by: Amit Daniel Kachhap Acked-by: Amit Daniel Kachhap Signed-off-by: Viresh Kumar Signed-off-by: Eduardo Valentin --- MAINTAINERS | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'MAINTAINERS') diff --git a/MAINTAINERS b/MAINTAINERS index 7ba7ab749c85..6cc919abf246 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -10338,6 +10338,16 @@ F: include/uapi/linux/thermal.h F: include/linux/cpu_cooling.h F: Documentation/devicetree/bindings/thermal/ +THERMAL/CPU_COOLING +M: Amit Daniel Kachhap +M: Viresh Kumar +M: Javi Merino +L: linux-pm@vger.kernel.org +S: Supported +F: Documentation/thermal/cpu-cooling-api.txt +F: drivers/thermal/cpu_cooling.c +F: include/linux/cpu_cooling.h + THINGM BLINK(1) USB RGB LED DRIVER M: Vivien Didelot S: Maintained -- cgit v1.2.3 From 562d897d15a6e2bab3cc9b4c172286b612834fe8 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Tue, 15 Sep 2015 10:50:14 -0600 Subject: net: Add documentation for VRF device Signed-off-by: David Ahern Signed-off-by: David S. Miller --- MAINTAINERS | 1 + 1 file changed, 1 insertion(+) (limited to 'MAINTAINERS') diff --git a/MAINTAINERS b/MAINTAINERS index 310da4295c70..d4d9d4f6d271 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11243,6 +11243,7 @@ L: netdev@vger.kernel.org S: Maintained F: drivers/net/vrf.c F: include/net/vrf.h +F: Documentation/networking/vrf.txt VT1211 HARDWARE MONITOR DRIVER M: Juerg Haefliger -- cgit v1.2.3 From 0526109a24eb07984f9e79852767300c8b8144de Mon Sep 17 00:00:00 2001 From: Cyril Hrubis Date: Thu, 17 Sep 2015 16:01:57 -0700 Subject: MAINTAINERS: update LTP mailing list [akpm@linux-foundation.org: Wanlong Gao has moved] Signed-off-by: Cyril Hrubis Cc: Jan Stancek Cc: Stanislav Kholmanskikh Cc: Alexey Kodanev Cc: Wanlong Gao Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- MAINTAINERS | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'MAINTAINERS') diff --git a/MAINTAINERS b/MAINTAINERS index 7ba7ab749c85..274f85405584 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -6452,11 +6452,11 @@ F: drivers/hwmon/ltc4261.c LTP (Linux Test Project) M: Mike Frysinger M: Cyril Hrubis -M: Wanlong Gao +M: Wanlong Gao M: Jan Stancek M: Stanislav Kholmanskikh M: Alexey Kodanev -L: ltp-list@lists.sourceforge.net (subscribers-only) +L: ltp@lists.linux.it (subscribers-only) W: http://linux-test-project.github.io/ T: git git://github.com/linux-test-project/ltp.git S: Maintained -- cgit v1.2.3 From c38f6ac74c99801360705d97244ff222ae18dc97 Mon Sep 17 00:00:00 2001 From: Michael Grzeschik Date: Thu, 17 Sep 2015 15:26:16 +0200 Subject: MAINTAINERS: add arcnet and take maintainership Add entry for arcnet to MAINTAINERS file and add myself as the maintainer of the subsystem. Signed-off-by: Michael Grzeschik Cc: davem@davemloft.net Cc: joe@perches.com Signed-off-by: David S. Miller --- MAINTAINERS | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'MAINTAINERS') diff --git a/MAINTAINERS b/MAINTAINERS index d4d9d4f6d271..c6aca87cd48a 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -808,6 +808,13 @@ S: Maintained F: drivers/video/fbdev/arcfb.c F: drivers/video/fbdev/core/fb_defio.c +ARCNET NETWORK LAYER +M: Michael Grzeschik +L: netdev@vger.kernel.org +S: Maintained +F: drivers/net/arcnet/ +F: include/uapi/linux/if_arcnet.h + ARM MFM AND FLOPPY DRIVERS M: Ian Molton S: Maintained -- cgit v1.2.3 From 6cf35642147103195f126d13bdc1d4c32c7c6666 Mon Sep 17 00:00:00 2001 From: Jiri Benc Date: Thu, 17 Sep 2015 16:28:31 +0200 Subject: MAINTAINERS: remove bouncing email address for qlcnic I got this automated message from when submitting a qlcnic patch: > Shahed Shaikh is no longer with QLogic. If you require assistance please > contact Ariel Elior Ariel.Elior@qlogic.com There's no point in having a bouncing address in MAINTAINERS. CC: Dept-GELinuxNICDev@qlogic.com CC: Ariel Elior Signed-off-by: Jiri Benc Signed-off-by: David S. Miller --- MAINTAINERS | 1 - 1 file changed, 1 deletion(-) (limited to 'MAINTAINERS') diff --git a/MAINTAINERS b/MAINTAINERS index c6aca87cd48a..e1c9fbb8bf92 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -8497,7 +8497,6 @@ F: Documentation/networking/LICENSE.qla3xxx F: drivers/net/ethernet/qlogic/qla3xxx.* QLOGIC QLCNIC (1/10)Gb ETHERNET DRIVER -M: Shahed Shaikh M: Dept-GELinuxNICDev@qlogic.com L: netdev@vger.kernel.org S: Supported -- cgit v1.2.3 From f0e03dbd2d61d991bdd2d76b4e84681fe3077176 Mon Sep 17 00:00:00 2001 From: Richard Fitzgerald Date: Tue, 22 Sep 2015 15:30:33 +0100 Subject: MAINTAINERS: Update website and git repo for Wolfson Microelectronics Support for Wolfson Microelectronics devices is now part of Cirrus Logic and the relevant parts of the old opensource.wolfsonmicro.com site have moved to the Cirrus Logic GitHub area. This patch updates the website and git repo links, and also removes an obsolete website link for the voltage and current drivers. Signed-off-by: Richard Fitzgerald Signed-off-by: Mark Brown --- MAINTAINERS | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) (limited to 'MAINTAINERS') diff --git a/MAINTAINERS b/MAINTAINERS index 7ba7ab749c85..dffea210e439 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11239,7 +11239,6 @@ VOLTAGE AND CURRENT REGULATOR FRAMEWORK M: Liam Girdwood M: Mark Brown L: linux-kernel@vger.kernel.org -W: http://opensource.wolfsonmicro.com/node/15 W: http://www.slimlogic.co.uk/?p=48 T: git git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git S: Supported @@ -11368,17 +11367,15 @@ WM97XX TOUCHSCREEN DRIVERS M: Mark Brown M: Liam Girdwood L: linux-input@vger.kernel.org -T: git git://opensource.wolfsonmicro.com/linux-2.6-touch -W: http://opensource.wolfsonmicro.com/node/7 +W: https://github.com/CirrusLogic/linux-drivers/wiki S: Supported F: drivers/input/touchscreen/*wm97* F: include/linux/wm97xx.h WOLFSON MICROELECTRONICS DRIVERS L: patches@opensource.wolfsonmicro.com -T: git git://opensource.wolfsonmicro.com/linux-2.6-asoc -T: git git://opensource.wolfsonmicro.com/linux-2.6-audioplus -W: http://opensource.wolfsonmicro.com/content/linux-drivers-wolfson-devices +T: git https://github.com/CirrusLogic/linux-drivers.git +W: https://github.com/CirrusLogic/linux-drivers/wiki S: Supported F: Documentation/hwmon/wm83?? F: arch/arm/mach-s3c64xx/mach-crag6410* -- cgit v1.2.3