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From: Thomas Monjalon <thomas@monjalon.net>
To: Stephen Hemminger <stephen@networkplumber.org>,
	Yoav Winstein <yoav.w@claroty.com>,
	Konstantin Ananyev <konstantin.v.ananyev@yandex.ru>
Cc: dev@dpdk.org
Subject: Re: [PATCH] bpf: don't verify classic bpfs
Date: Thu, 27 Jun 2024 17:36:43 +0200	[thread overview]
Message-ID: <4846180.STdkYbjpsp@thomas> (raw)
In-Reply-To: <2eaeaf90d9a94c8ca199f5bb51e0ba38@huawei.com>

16/05/2024 11:36, Konstantin Ananyev:
> 
> > On Sun, 12 May 2024 08:55:45 +0300
> > Yoav Winstein <yoav.w@claroty.com> wrote:
> > 
> > > When classic BPFs with lots of branching instructions are compiled,
> > > __rte_bpf_bpf_validate runs way too slow. A simple bpf such as:
> > > 'ether host a0:38:6d:af:17:eb or b3:a3:ff:b6:c1:ef or ...' 12 times
> > >
> > > results in ~1 minute of bpf validation.
> > > This patch makes __rte_bpf_bpf_validate be aware of bpf_prm originating
> > > from classic BPF, allowing to safely skip over the validation.
> > >
> > > Signed-off-by: Yoav Winstein <yoav.w@claroty.com>
> > > ---
> > 
> > No.
> > Wallpapering over a performance bug in the BPF library is not
> > the best way to handle this. Please analyze the problem in the BPF
> > library; it should be fixed there.
> 
> +1
> Blindly disabling verification for all cBPFs is the worst possible option here.
> We need at least try to understand what exactly causing such slowdown.

+1

You didn't mention it is also breaking ABI compatibility.




  reply	other threads:[~2024-06-27 15:36 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-05-12  5:55 Yoav Winstein
2024-05-12 16:03 ` Stephen Hemminger
2024-05-16  9:36   ` Konstantin Ananyev
2024-06-27 15:36     ` Thomas Monjalon [this message]
2024-06-27 18:14       ` Konstantin Ananyev
  -- strict thread matches above, loose matches on Subject: below --
2024-05-12  6:00 Yoav Winstein
2024-05-12  5:51 Yoav Winstein
2024-05-12  5:35 Yoav Winstein

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