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From: Thomas Monjalon <thomas.monjalon@6wind.com>
To: Tomasz Kulasek <tomaszx.kulasek@intel.com>
Cc: dev@dpdk.org, ian.betts@intel.com
Subject: Re: [PATCH] examples/performance-thread: fix segfault with in gcc 5.x
Date: Wed, 27 Apr 2016 17:34:25 +0200	[thread overview]
Message-ID: <5958766.CmHbfFznCf@xps13> (raw)
In-Reply-To: <1461685676-7084-1-git-send-email-tomaszx.kulasek@intel.com>

2016-04-26 17:47, Tomasz Kulasek:
> It seems that with gcc >5.x and -O2/-O3 optimization breaks packet grouping
> algorithm in l3fwd-thread application causing segfault.
> 
> When last packet pointer "lp" and "pnum->u64" buffer points the same
> memory buffer, high optimization can cause unpredictable results. It seems
> that assignment of precalculated group sizes may interfere with
> initialization of new group size when lp points value inside current group
> and didn't should be changed.
> 
> With gcc >5.x and optimization we cannot be sure which assignment will be
> done first, so the group size can be counted incorrectly causing segfault.
> 
> This patch eliminates intersection of assignment of initial group size
> (lp[0] = 1) and precalculated group sizes when gptbl[v].idx < 4.
> 
> Fixes: d48415e1fee3 ("examples/performance-thread: add l3fwd-thread app")
> 
> Signed-off-by: Tomasz Kulasek <tomaszx.kulasek@intel.com>

Same patch as af1694d94 (for original l3fwd).
Applied, thanks

      reply	other threads:[~2016-04-27 15:34 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-04-26 15:47 [PATCH] examples/performance-thread: fix segfault with in gcc 5.x Tomasz Kulasek
2016-04-27 15:34 ` Thomas Monjalon [this message]

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