From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexei Starovoitov Subject: Re: [PATCH net-next] test_bpf: indicate whether bpf prog got jited in test suite Date: Thu, 30 Apr 2015 10:10:46 -0700 Message-ID: <55426216.3080003@plumgrid.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, Nicolas Schichan To: Daniel Borkmann , davem@davemloft.net Return-path: Received: from mail-ig0-f178.google.com ([209.85.213.178]:36907 "EHLO mail-ig0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751272AbbD3RKr (ORCPT ); Thu, 30 Apr 2015 13:10:47 -0400 Received: by igblo3 with SMTP id lo3so19091063igb.0 for ; Thu, 30 Apr 2015 10:10:46 -0700 (PDT) In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On 4/30/15 7:17 AM, Daniel Borkmann wrote: > I think this is useful to verify whether a filter could be JITed or > not in case of bpf_prog_enable >= 1, which otherwise the test suite > doesn't tell besides taking a good peek at the performance numbers. > > Nicolas Schichan reported a bug in the ARM JIT compiler that rejected > and waved the filter to the interpreter although it shouldn't have. > Nevertheless, the test passes as expected, but such information is > not visible. > > It's i.e. useful for the remaining classic JITs, but also for > implementing remaining opcodes that are not yet present in eBPF JITs > (e.g. ARM64 waves some of them to the interpreter). This minor patch > allows to grep through dmesg to find those accordingly, but also > provides a total summary, i.e.: [/53 JIT'ed] > > # echo 1 > /proc/sys/net/core/bpf_jit_enable > # insmod lib/test_bpf.ko > # dmesg | grep "jited:0" > > dmesg example on the ARM issue with JIT rejection: > > [...] > [ 67.925387] test_bpf: #2 ADD_SUB_MUL_K jited:1 24 PASS > [ 67.930889] test_bpf: #3 DIV_MOD_KX jited:0 794 PASS > [ 67.943940] test_bpf: #4 AND_OR_LSH_K jited:1 20 20 PASS > [...] > > Signed-off-by: Daniel Borkmann > Cc: Nicolas Schichan > Cc: Alexei Starovoitov yeah. definitely useful addition. Acked-by: Alexei Starovoitov