How to compile perf for Android ========================================= I. Set the Android NDK environment ------------------------------------------------ (a). Use the Android NDK ------------------------------------------------ 1. You need to download and install the Android Native Development Kit (NDK). Set the NDK variable to point to the path where you installed the NDK: export NDK=/path/to/android-ndk 2. Set cross-compiling environment variables for NDK toolchain and sysroot. For arm: export NDK_TOOLCHAIN=${NDK}/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64/bin/arm-linux-androideabi- export NDK_SYSROOT=${NDK}/platforms/android-24/arch-arm For x86: export NDK_TOOLCHAIN=${NDK}/toolchains/x86-4.9/prebuilt/linux-x86_64/bin/i686-linux-android- export NDK_SYSROOT=${NDK}/platforms/android-24/arch-x86 This method is only tested for Android NDK versions Revision 11b and later. perf uses some bionic enhancements that are not included in prior NDK versions. You can use method (b) described below instead. (b). Use the Android source tree ----------------------------------------------- 1. Download the master branch of the Android source tree. Set the environment for the target you want using: source build/envsetup.sh lunch 2. Build your own NDK sysroot to contain latest bionic changes and set the NDK sysroot environment variable. cd ${ANDROID_BUILD_TOP}/ndk For arm: ./build/tools/build-ndk-sysroot.sh --abi=arm export NDK_SYSROOT=${ANDROID_BUILD_TOP}/ndk/build/platforms/android-3/arch-arm For x86: ./build/tools/build-ndk-sysroot.sh --abi=x86 export NDK_SYSROOT=${ANDROID_BUILD_TOP}/ndk/build/platforms/android-3/arch-x86 3. Set the NDK toolchain environment variable. For arm: export NDK_TOOLCHAIN=${ANDROID_TOOLCHAIN}/arm-linux-androideabi- For x86: export NDK_TOOLCHAIN=${ANDROID_TOOLCHAIN}/i686-linux-android- II. Compile perf for Android ------------------------------------------------ You need to run make with the NDK toolchain and sysroot defined above: For arm: make WERROR=0 ARCH=arm CROSS_COMPILE=${NDK_TOOLCHAIN} EXTRA_CFLAGS="-pie --sysroot=${NDK_SYSROOT}" For x86: make WERROR=0 ARCH=x86 CROSS_COMPILE=${NDK_TOOLCHAIN} EXTRA_CFLAGS="-pie --sysroot=${NDK_SYSROOT}" III. Install perf ----------------------------------------------- You need to connect to your Android device/emulator using adb. Install perf using: adb push perf /data/perf If you also want to use perf-archive you need busybox tools for Android. For installing perf-archive, you first need to replace #!/bin/bash with #!/system/bin/sh: sed 's/#!\/bin\/bash/#!\/system\/bin\/sh/g' perf-archive >> /tmp/perf-archive chmod +x /tmp/perf-archive adb push /tmp/perf-archive /data/perf-archive IV. Environment settings for running perf ------------------------------------------------ Some perf features need environment variables to run properly. You need to set these before running perf on the target: adb shell # PERF_PAGER=cat IV. Run perf ------------------------------------------------ Run perf on your device/emulator to which you previously connected using adb: # ./data/perf d2b04e070bc040319aaebfec09e0144dc3341'>include/uapi/rdma/mlx5-abi.h
diff options
context:
space:
mode:
authorDouglas Miller <dougmill@linux.vnet.ibm.com>2017-01-28 06:42:20 -0600
committerTejun Heo <tj@kernel.org>2017-01-28 07:49:42 -0500
commit966d2b04e070bc040319aaebfec09e0144dc3341 (patch)
tree4b96156e3d1dd4dfd6039b7c219c9dc4616da52d /include/uapi/rdma/mlx5-abi.h
parent1b1bc42c1692e9b62756323c675a44cb1a1f9dbd (diff)
percpu-refcount: fix reference leak during percpu-atomic transition
percpu_ref_tryget() and percpu_ref_tryget_live() should return "true" IFF they acquire a reference. But the return value from atomic_long_inc_not_zero() is a long and may have high bits set, e.g. PERCPU_COUNT_BIAS, and the return value of the tryget routines is bool so the reference may actually be acquired but the routines return "false" which results in a reference leak since the caller assumes it does not need to do a corresponding percpu_ref_put(). This was seen when performing CPU hotplug during I/O, as hangs in blk_mq_freeze_queue_wait where percpu_ref_kill (blk_mq_freeze_queue_start) raced with percpu_ref_tryget (blk_mq_timeout_work). Sample stack trace: __switch_to+0x2c0/0x450 __schedule+0x2f8/0x970 schedule+0x48/0xc0 blk_mq_freeze_queue_wait+0x94/0x120 blk_mq_queue_reinit_work+0xb8/0x180 blk_mq_queue_reinit_prepare+0x84/0xa0 cpuhp_invoke_callback+0x17c/0x600 cpuhp_up_callbacks+0x58/0x150 _cpu_up+0xf0/0x1c0 do_cpu_up+0x120/0x150 cpu_subsys_online+0x64/0xe0 device_online+0xb4/0x120 online_store+0xb4/0xc0 dev_attr_store+0x68/0xa0 sysfs_kf_write+0x80/0xb0 kernfs_fop_write+0x17c/0x250 __vfs_write+0x6c/0x1e0 vfs_write+0xd0/0x270 SyS_write+0x6c/0x110 system_call+0x38/0xe0 Examination of the queue showed a single reference (no PERCPU_COUNT_BIAS, and __PERCPU_REF_DEAD, __PERCPU_REF_ATOMIC set) and no requests. However, conditions at the time of the race are count of PERCPU_COUNT_BIAS + 0 and __PERCPU_REF_DEAD and __PERCPU_REF_ATOMIC set. The fix is to make the tryget routines use an actual boolean internally instead of the atomic long result truncated to a int. Fixes: e625305b3907 percpu-refcount: make percpu_ref based on longs instead of ints Link: https://bugzilla.kernel.org/show_bug.cgi?id=190751 Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com> Reviewed-by: Jens Axboe <axboe@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: e625305b3907 ("percpu-refcount: make percpu_ref based on longs instead of ints") Cc: stable@vger.kernel.org # v3.18+
Diffstat (limited to 'include/uapi/rdma/mlx5-abi.h')