Re: [EXTERNAL] Re: [PATCH v5 1/1] examples/l2fwd-jobstats: fix lock availability

[Nithin Dabilpuram <nithind1988@gmail.com>]

Acked-by: Nithin Dabilpuram <ndabilpuram@marvell.com>

On Mon, Oct 21, 2024 at 12:43 PM Rakesh Kudurumalla
<rkudurumalla@marvell.com> wrote:
>
> ping
>
> > -----Original Message-----
> > From: Rakesh Kudurumalla
> > Sent: Friday, August 16, 2024 10:55 AM
> > To: Stephen Hemminger <stephen@networkplumber.org>
> > Cc: ferruh.yigit@amd.com; andrew.rybchenko@oktetlabs.ru;
> > orika@nvidia.com; thomas@monjalon.net; dev@dpdk.org; Jerin Jacob
> > <jerinj@marvell.com>; Nithin Kumar Dabilpuram
> > <ndabilpuram@marvell.com>; stable@dpdk.org
> > Subject: RE: [EXTERNAL] Re: [PATCH v5 1/1] examples/l2fwd-jobstats: fix lock
> > availability
> >
> >
> >
> > > -----Original Message-----
> > > From: Stephen Hemminger <stephen@networkplumber.org>
> > > Sent: Sunday, August 11, 2024 9:47 PM
> > > To: Rakesh Kudurumalla <rkudurumalla@marvell.com>
> > > Cc: ferruh.yigit@amd.com; andrew.rybchenko@oktetlabs.ru;
> > > orika@nvidia.com; thomas@monjalon.net; dev@dpdk.org; Jerin Jacob
> > > <jerinj@marvell.com>; Nithin Kumar Dabilpuram
> > > <ndabilpuram@marvell.com>; stable@dpdk.org
> > > Subject: [EXTERNAL] Re: [PATCH v5 1/1] examples/l2fwd-jobstats: fix
> > > lock availability
> > >
> > > On Sun, 11 Aug 2024 21: 29: 57 +0530 Rakesh Kudurumalla
> > <rkudurumalla@
> > > marvell. com> wrote: > Race condition between jobstats and time
> > > metrics > for forwarding and flushing is maintained using spinlock.
> > > > Timer metrics are not displayed
> > > On Sun, 11 Aug 2024 21:29:57 +0530
> > > Rakesh Kudurumalla <rkudurumalla@marvell.com> wrote:
> > >
> > > > Race condition between jobstats and time metrics for forwarding and
> > > > flushing is maintained using spinlock.
> > > > Timer metrics are not displayed properly due to the frequent
> > > > unavailability of the lock.This patch fixes the issue by introducing
> > > > a delay before acquiring the lock in the loop. This delay allows for
> > > > betteravailability of the lock, ensuring that show_lcore_stats() can
> > > > periodically update the statistics even when forwarding jobs are
> > > > running.
> > > >
> > > > Fixes: 204896f8d66c ("examples/l2fwd-jobstats: add new example")
> > > > Cc: stable@dpdk.org
> > > >
> > > > Signed-off-by: Rakesh Kudurumalla <rkudurumalla@marvell.com>
> > >
> > > Would be better if this code used RCU and not a lock
> >
> > Currently the jobstats app uses the lock only for collecting single snapshot of
> > different statistics and printing the same from main core. With RCU since we
> > cannot pause the worker core to collect such a single snapshot, integrating
> > RCU would need a full redesign of the application and would take lot of
> > effort.