On Thu, 19 Jan 2017 08:06:21 -0800 Roopa Prabhu <ro...@cumulusnetworks.com> wrote:
> On 1/19/17, 7:21 AM, Nogah Frankel wrote: > >> -----Original Message----- > >> From: Nogah Frankel > >> Sent: Sunday, January 15, 2017 3:55 PM > >> To: 'Stephen Hemminger' <step...@networkplumber.org> > >> Cc: netdev@vger.kernel.org; roszenr...@gmail.com; > >> ro...@cumulusnetworks.com; Jiri > >> Pirko <j...@mellanox.com>; Ido Schimmel <ido...@mellanox.com>; Elad Raz > >> <el...@mellanox.com>; Yotam Gigi <yot...@mellanox.com>; Or Gerlitz > >> <ogerl...@mellanox.com> > >> Subject: RE: [PATCH iproute2 v4 3/4] ifstat: Add 64 bits based stats to > >> extended statistics > >> > >> > >> > >>> -----Original Message----- > >>> From: Stephen Hemminger [mailto:step...@networkplumber.org] > >>> Sent: Friday, January 13, 2017 3:44 AM > >>> To: Nogah Frankel <nog...@mellanox.com> > >>> Cc: netdev@vger.kernel.org; roszenr...@gmail.com; > >>> ro...@cumulusnetworks.com; > >> Jiri > >>> Pirko <j...@mellanox.com>; Ido Schimmel <ido...@mellanox.com>; Elad Raz > >>> <el...@mellanox.com>; Yotam Gigi <yot...@mellanox.com>; Or Gerlitz > >>> <ogerl...@mellanox.com> > >>> Subject: Re: [PATCH iproute2 v4 3/4] ifstat: Add 64 bits based stats to > >>> extended statistics > >>> > >>> On Thu, 12 Jan 2017 15:49:50 +0200 > >>> Nogah Frankel <nog...@mellanox.com> wrote: > >>> > >>>> The default stats for ifstat are 32 bits based. > >>>> The kernel supports 64 bits based stats. (They are returned in struct > >>>> rtnl_link_stats64 which is an exact copy of struct rtnl_link_stats, in > >>>> which the "normal" stats are returned, but with fields of u64 instead of > >>>> u32). This patch adds them as an extended stats. > >>>> > >>>> It is read with filter type IFLA_STATS_LINK_64 and no sub type. > >>>> > >>>> It is under the name 64bits > >>>> (or any shorten of it as "64") > >>>> > >>>> For example: > >>>> ifstat -x 64bit > >>>> > >>>> Signed-off-by: Nogah Frankel <nog...@mellanox.com> > >>>> Reviewed-by: Jiri Pirko <j...@mellanox.com> > >>> Other commands (like ip link) always use the 64 bit statistics if > >>> available > >>> from the device. I see no reason that ifstat needs to be different. > >>> > >> Do you mean to change the default ifstat results to be 64 bits based? > >> I tried it in the first version, but Roopa commented that it was not a > >> good idea. > >> She said they tried it in the past and it caused backward compatibilities > >> problems. > >> (Or maybe I didn't understand correctly) > > So, can I leave the default ifstat results to be 32 bits based, for the > > time being? > > > From past discussions: Moving the default to 64bit has compat issues with the > old history file. > There is a way to make it work by using a new file header (to indicate that > it is 64 bit) in > a freshly created history file and also check this header before dumping > stats into the history file. > ie maintain backward compat without introducing a new option. It is doable. > > One approach is, you can drop the 64bit option from this series and > try updating the default to 64 bit (with compat handling code) in a later > series. The ifstat code could do conversion based on file size. if (history_file_is_32bit()) { printf("converting to 64 bit format\n"); ... }
