Messages in this thread | | | Date | Fri, 20 Nov 2015 10:22:26 +0800 | From | "Wangnan (F)" <> | Subject | Re: [PATCH] perf test: Add bpf-output event |
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On 2015/11/20 7:29, Sukadev Bhattiprolu wrote: > Wangnan (F) [wangnan0@huawei.com] wrote: > | > | > | On 2015/11/19 7:14, Alexei Starovoitov wrote: > | >On Wed, Nov 18, 2015 at 05:50:39PM -0300, Arnaldo Carvalho de Melo wrote: > | >>Em Wed, Nov 18, 2015 at 11:26:04AM -0800, Sukadev Bhattiprolu escreveu: > | >>>>From 8f71d55dd3e27e6ca2138e3ed6dfeceb1c00a426 Mon Sep 17 00:00:00 2001 > | >>>From: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> > | >>>Date: Wed, 18 Nov 2015 19:06:08 -0500 > | >>>Subject: [PATCH] perf test: Add bpf-output event > | >>> > | >>>The kernel has added support for 'PERF_COUNT_SW_BPF_OUTPUT' but that is > | >>>missing from the perf tool. Among other things, results in the 'roundtrip > | >>>evsel->name check' test case of 'perf test' failing on Powerpc. > | >>Next time can you please state if this is for this merge window or for > | >>the next? > | >> > | >>Will apply it for perf/core, for the next merge window. > | >wait a sec, I believe Wang has posted an RFC a month ago that adds support > | >for this properly instead of simply shutting up the error. > | > | Yes. Please have a look at > | > | http://lkml.kernel.org/g/1446029705-199659-3-git-send-email-wangnan0@huawei.com > | > | and patch 23/31 - 31/31 in > | > | http://lkml.kernel.org/g/1444826502-49291-1-git-send-email-wangnan0@huawei.com > | > | We are working on a solution which truly utilizes bpf-output, including > | filling event array and extracting BPF output through perf data to CTF > | format. Now they are separated in multiple patchset, and I'd like to > | resend them to Arnaldo in this week. > > Ok. It looked like there was development going on around BPF so I put > in the stubs to avoid false positives in the perf test. There is a BPF > filter test case that is also getting Skipped. Would this patchset address > that too?
Do you mean this?
$ ./perf test bpf 37: Test BPF filter : 37.1: Test basic BPF filtering : Skip
To make it pass you need to build BPF compiling environment first.
First of all you must be root:
$ ./perf test -v bpf 37: Test BPF filter : 37.1: Test basic BPF filtering : --- start --- test child forked, pid 19359 Only root can run BPF test test child finished with -2 ---- end ---- Test BPF filter subtest 0: Skip
Then it would tell you how to setup your LLVM environment:
$ sudo -s # ./perf test -v bpf 37: Test BPF filter : 37.1: Test basic BPF filtering : --- start --- test child forked, pid 19463 ERROR: unable to find clang. Hint: Try to install latest clang/llvm to support BPF. Check your $PATH and 'clang-path' option in [llvm] section of ~/.perfconfig. LLVM 3.7 or newer is required. Which can be found from http://llvm.org You may want to try git trunk: git clone http://llvm.org/git/llvm.git and git clone http://llvm.org/git/clang.git
Or fetch the latest clang/llvm 3.7 from pre-built llvm packages for debian/ubuntu: http://llvm.org/apt
If you are using old version of clang, change 'clang-bpf-cmd-template' option in [llvm] section of ~/.perfconfig to:
"$CLANG_EXEC $CLANG_OPTIONS $KERNEL_INC_OPTIONS \ -working-directory $WORKING_DIR -c $CLANG_SOURCE \ -emit-llvm -o - | /path/to/llc -march=bpf -filetype=obj -o -" (Replace /path/to/llc with path to your llc)
Failed to compile test case: 'Basic BPF llvm compiling test' Unable to get BPF object, fix 'perf test LLVM' first test child finished with -2 ---- end ---- Test BPF filter subtest 0: Skip
Set your clang path to ~/.perfconfig
# cat ~/.perfconfig [llvm] clang-path = "/opt/llvm-3.7.0/x86_64-oe-linux-clang"
Then try 'perf test LLVM', fix all failure:
# ./perf test LLVM 35: Test LLVM searching and compiling : 35.1: Basic BPF llvm compiling test : Ok 35.2: Test kbuild searching : Ok 35.3: Compile source for BPF prologue generation test : Ok
After that you can try perf test BPF:
# ./perf test BPF 37: Test BPF filter : 37.1: Test basic BPF filtering : Ok 37.2: Test BPF prologue generation : Ok
Thank you.
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