netdev - Re: [PATCH v3] net: use bulk free in kfree_skb

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20190325164929.03d67fb6@carbon>
Date:   Mon, 25 Mar 2019 16:49:29 +0100
From:   Jesper Dangaard Brouer <brouer@...hat.com>
To:     Eric Dumazet <eric.dumazet@...il.com>
Cc:     Felix Fietkau <nbd@....name>, netdev@...r.kernel.org,
        davem@...emloft.net, fw@...len.de, pabeni@...hat.com,
        brouer@...hat.com
Subject: Re: [PATCH v3] net: use bulk free in kfree_skb_list

On Mon, 25 Mar 2019 02:27:14 -0700
Eric Dumazet <eric.dumazet@...il.com> wrote:

> > +#ifdef CONFIG_SLUB
> > +		/* SLUB writes into objects when freeing */
> > +		prefetchw(segs);
> > +#endif  
> 
> This is done too late : 
> You should probably either remove this prefetchw()
> or do it before reading segs->next at the beginning of the loop.

Agree. Not sure the prefetchw optimization makes sense here. IHMO just
drop it in this patch.

-- 
Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Principal Kernel Engineer at Red Hat
  LinkedIn: http://www.linkedin.com/in/brouer