From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexei Starovoitov Subject: Re: [PATCH net-next 7/7] samples/bpf: xdp_monitor tool based on tracepoints Date: Tue, 29 Aug 2017 10:05:52 -0700 Message-ID: <20170829170551.5uws25py4fcpem73@ast-mbp> References: <150401743083.16384.15778781741742858567.stgit@firesoul> <150401749138.16384.17129327124102881342.stgit@firesoul> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org, John Fastabend To: Jesper Dangaard Brouer Return-path: Received: from mail-pg0-f49.google.com ([74.125.83.49]:35874 "EHLO mail-pg0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750779AbdH2RFz (ORCPT ); Tue, 29 Aug 2017 13:05:55 -0400 Received: by mail-pg0-f49.google.com with SMTP id r133so12478647pgr.3 for ; Tue, 29 Aug 2017 10:05:55 -0700 (PDT) Content-Disposition: inline In-Reply-To: <150401749138.16384.17129327124102881342.stgit@firesoul> Sender: netdev-owner@vger.kernel.org List-ID: On Tue, Aug 29, 2017 at 04:38:11PM +0200, Jesper Dangaard Brouer wrote: > This tool xdp_monitor demonstrate how to use the different xdp_redirect > tracepoints xdp_redirect{,_map}{,_err} from a BPF program. > > The default mode is to only monitor the error counters, to avoid > affecting the per packet performance. Tracepoints comes with a base > overhead of 25 nanosec for an attached bpf_prog, and 48 nanosec for > using a full perf record (with non-matching filter). Thus, default > loading the --stats mode could affect the maximum performance. > > This version of the tool is very simple and count all types of errors > as one. It will be natural to extend this later with the different > types of errors that can occur, which should help users quickly > identify common mistakes. > > Because the TP_STRUCT was kept in sync all the tracepoints loads the > same BPF code. It would also be natural to extend the map version to > demonstrate how the map information could be used. > > Signed-off-by: Jesper Dangaard Brouer Nice. Did you consider using libbbpf (instead of old bpf_load.c hack) and make full standalone tool out of it? Looks very useful. Acked-by: Alexei Starovoitov