From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Ahern Subject: Re: [PATCH net-next] net: FIB tracepoints Date: Thu, 27 Aug 2015 22:12:01 -0700 Message-ID: <55DFEDA1.2070903@cumulusnetworks.com> References: <1440737972-10468-1-git-send-email-dsa@cumulusnetworks.com> <20150827.220538.2154843333132928646.davem@davemloft.net> <55DFEC92.8050700@cumulusnetworks.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: David Miller Return-path: Received: from mail-pa0-f50.google.com ([209.85.220.50]:32863 "EHLO mail-pa0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750698AbbH1FMD (ORCPT ); Fri, 28 Aug 2015 01:12:03 -0400 Received: by padfo6 with SMTP id fo6so11199438pad.0 for ; Thu, 27 Aug 2015 22:12:02 -0700 (PDT) In-Reply-To: <55DFEC92.8050700@cumulusnetworks.com> Sender: netdev-owner@vger.kernel.org List-ID: On 8/27/15 10:07 PM, David Ahern wrote: > On 8/27/15 10:05 PM, David Miller wrote: >> From: David Ahern >> Date: Thu, 27 Aug 2015 21:59:32 -0700 >> >>> + __array( __u8, src, 4 ) >>> + __array( __u8, dst, 4 ) >> ... >>> + __array( __u8, src, 4 ) >> >> Maybe there is something I don't understand about tracing, but why not >> use __u32? If endianness types are the issue, just force cast it as >> needed. >> >> Using a memcpy() on a 4-byte array is kinda excessive. >> > > Silly trick need to use %pI4. ie., printing the addresses as strings vs. > hex. perhaps an example helps: swapper 0 [000] 406.447548: fib:fib_table_lookup: table 255 oif 0 iif 0 src 0.0.0.0 dst 2.1.1.2 tos 0 scope 0 flags 0 If src and dst are u32's then they print as either 0x%x or %d which is not intuitive. I added support to perf for the following printk formats with 3d199b5be53: %pi4 print an IPv4 address with leading zeros %pI4 print an IPv4 address without leading zeros %pi6 print an IPv6 address without colons %pI6 print an IPv6 address with colons %pI6c print an IPv6 address in compressed form with colons %pISpc print an IP address from a sockaddr