Re: [PATCH] perf test: Switch basic bpf filtering test to use syscall tracepoint

From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: kajoljain <kjain@linux.ibm.com>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>,
	Disha Goel <disgoel@linux.vnet.ibm.com>,
	linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
	bpf@vger.kernel.org
Subject: Re: [PATCH] perf test: Switch basic bpf filtering test to use syscall tracepoint
Date: Mon, 30 Jan 2023 11:09:45 -0300	[thread overview]
Message-ID: <Y9fPqaZ1MksBX/lx@kernel.org> (raw)
In-Reply-To: <70b60459-2e7a-1944-77dc-54fef2e00975@linux.ibm.com>

Em Mon, Jan 30, 2023 at 02:28:49PM +0530, kajoljain escreveu:
> 
> 
> On 1/23/23 14:02, Naveen N. Rao wrote:
> > BPF filtering tests can sometime fail. Running the test in verbose mode
> > shows the following:
> >   $ sudo perf test 42
> >   42: BPF filter                                                      :
> >   42.1: Basic BPF filtering                                           : FAILED!
> >   42.2: BPF pinning                                                   : Skip
> >   42.3: BPF prologue generation                                       : Skip
> >   $ perf --version
> >   perf version 4.18.0-425.3.1.el8.ppc64le
> >   $ sudo perf test -v 42
> >   42: BPF filter                                                      :
> >   42.1: Basic BPF filtering                                           :
> >   --- start ---
> >   test child forked, pid 711060
> >   ...
> >   bpf: config 'func=do_epoll_wait' is ok
> >   Looking at the vmlinux_path (8 entries long)
> >   Using /usr/lib/debug/lib/modules/4.18.0-425.3.1.el8.ppc64le/vmlinux for symbols
> >   Open Debuginfo file: /usr/lib/debug/.build-id/81/56f5a07f92ccb62c5600ba0e4aacfb5f3a7534.debug
> >   Try to find probe point from debuginfo.
> >   Matched function: do_epoll_wait [4ef8cb0]
> >   found inline addr: 0xc00000000061dbe4
> >   Probe point found: __se_compat_sys_epoll_pwait+196
> >   found inline addr: 0xc00000000061d9f4
> >   Probe point found: __se_sys_epoll_pwait+196
> >   found inline addr: 0xc00000000061d824
> >   Probe point found: __se_sys_epoll_wait+36
> >   Found 3 probe_trace_events.
> >   Opening /sys/kernel/tracing//kprobe_events write=1
> >   ...
> >   BPF filter result incorrect, expected 56, got 56 samples
> >   test child finished with -1
> >   ---- end ----
> >   BPF filter subtest 1: FAILED!
> 
> Patch looks good to me.
> 
> Reviewed-by: Kajol Jain<kjain@linux.ibm.com>

Thanks, added to that cset, as it is still just on tmp.perf/core.

- Arnaldo