From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932778AbcLPBtG convert rfc822-to-8bit (ORCPT ); Thu, 15 Dec 2016 20:49:06 -0500 Received: from relay4-d.mail.gandi.net ([217.70.183.196]:40461 "EHLO relay4-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755838AbcLPBs6 (ORCPT ); Thu, 15 Dec 2016 20:48:58 -0500 X-Originating-IP: 209.85.217.176 MIME-Version: 1.0 In-Reply-To: References: <20161214224342.12858-1-joe@ovn.org> <20161214224342.12858-3-joe@ovn.org> <20161215155022.GE6866@kernel.org> <20161215182918.GG6866@kernel.org> <20161215183440.GH6866@kernel.org> From: Joe Stringer Date: Thu, 15 Dec 2016 17:48:31 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH perf/core REBASE 2/5] samples/bpf: Switch over to libbpf To: Arnaldo Carvalho de Melo Cc: LKML , netdev , Wang Nan , ast@fb.com, Daniel Borkmann , Arnaldo Carvalho de Melo Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 15 December 2016 at 14:00, Joe Stringer wrote: > On 15 December 2016 at 10:34, Arnaldo Carvalho de Melo wrote: >> Em Thu, Dec 15, 2016 at 03:29:18PM -0300, Arnaldo Carvalho de Melo escreveu: >>> Em Thu, Dec 15, 2016 at 12:50:22PM -0300, Arnaldo Carvalho de Melo escreveu: >>> > Em Wed, Dec 14, 2016 at 02:43:39PM -0800, Joe Stringer escreveu: >>> > > Now that libbpf under tools/lib/bpf/* is synced with the version from >>> > > samples/bpf, we can get rid most of the libbpf library here. >>> > > >>> > > Signed-off-by: Joe Stringer >>> > > Cc: Alexei Starovoitov >>> > > Cc: Daniel Borkmann >>> > > Cc: Wang Nan >>> > > Link: http://lkml.kernel.org/r/20161209024620.31660-6-joe@ovn.org >>> > > [ Use -I$(srctree)/tools/lib/ to support out of source code tree builds, as noticed by Wang Nan ] >>> >>> So, the above comment no longer applied to this adjusted patch from you, >>> as you removed one hunk too much, that, after applied, gets samples/bpf/ >>> to build successfully: >>> >>> diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile >>> index add514e2984a..81b0ef2f7994 100644 >>> --- a/samples/bpf/Makefile >>> +++ b/samples/bpf/Makefile >>> @@ -107,6 +107,7 @@ always += lwt_len_hist_kern.o >>> always += xdp_tx_iptunnel_kern.o >>> >>> HOSTCFLAGS += -I$(objtree)/usr/include >>> +HOSTCFLAGS += -I$(srctree)/tools/lib/ >>> HOSTCFLAGS += -I$(srctree)/tools/testing/selftests/bpf/ >>> >>> HOSTCFLAGS_bpf_load.o += -I$(objtree)/usr/include -Wno-unused-variable >>> >>> --------------------- >>> >>> I added it, continuing... >> >> But then, when I tried to run offwaketime with it, it fails: >> >> [root@jouet bpf]# ./offwaketime ls >> bpf_load_program() err=22 >> BPF_LDX uses reserved fields >> bpf_load_program() err=22 >> BPF_LDX uses reserved fields >> [root@jouet bpf]# >> >> If I remove this patch and try again, it works: >> >> [root@jouet bpf]# ./offwaketime | head -4 >> swapper/1;start_secondary;cpu_startup_entry;schedule_preempt_disabled;schedule;__schedule;-;---;; 46 >> chrome;return_from_SYSCALL_64;do_syscall_64;exit_to_usermode_loop;schedule;__schedule;-;try_to_wake_up;do_futex;sys_futex;do_syscall_64;return_from_SYSCALL_64;;Chrome_ChildIOT 1 >> firefox;entry_SYSCALL_64_fastpath;sys_poll;do_sys_poll;poll_schedule_timeout;schedule_hrtimeout_range;schedule_hrtimeout_range_clock;schedule;__schedule;-;try_to_wake_up;pollwake;__wake_up_common;__wake_up_sync_key;pipe_write;__vfs_write;vfs_write;sys_write;entry_SYSCALL_64_fastpath;;Timer 3 >> dockerd-current;entry_SYSCALL_64_fastpath;sys_select;core_sys_select;do_select;poll_schedule_timeout;schedule_hrtimeout_range;schedule_hrtimeout_range_clock;schedule;__schedule;-;try_to_wake_up;futex_wake;do_futex;sys_futex;entry_SYSCALL_64_fastpath;;dockerd-current 2 >> [root@jouet bpf]# >> >> >> So, I'm stopping here so that I can push what I have to Ingo, then I'll get >> back to this, hopefully by then you beat me and I have just to retest 8-) > > OK, thanks for the report. Looks like there was another difference > between the two libbpfs - one used total program size for its > load_program API; the actual kernel API uses instruction count. This > incremental should do the trick: > > https://github.com/joestringer/linux/commit/6ff7726f20077bed66fb725f5189c13690154b6a The full branch with this change (fast-forward from your tmp branch) is available here: https://github.com/joestringer/linux/tree/submit/libbpf_samples_v5 I tried running every selftest and BPF sample I could get my hands on; there's one or two that I couldn't run, but seemed more to do with my versions of TC/iproute and kernel config rather than libbpf changes. Let me know if you see any further trouble.