netdev - Re: [PATCH 0/6 v3] kvmalloc

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Message-ID: <20170130075626.GC8443@dhcp22.suse.cz>
Date:   Mon, 30 Jan 2017 08:56:27 +0100
From:   Michal Hocko <mhocko@...nel.org>
To:     Daniel Borkmann <daniel@...earbox.net>
Cc:     Alexei Starovoitov <alexei.starovoitov@...il.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Vlastimil Babka <vbabka@...e.cz>, Mel Gorman <mgorman@...e.de>,
        Johannes Weiner <hannes@...xchg.org>,
        linux-mm <linux-mm@...ck.org>,
        LKML <linux-kernel@...r.kernel.org>,
        "netdev@...r.kernel.org" <netdev@...r.kernel.org>,
        marcelo.leitner@...il.com
Subject: Re: [PATCH 0/6 v3] kvmalloc

On Fri 27-01-17 21:12:26, Daniel Borkmann wrote:
> On 01/27/2017 11:05 AM, Michal Hocko wrote:
> > On Thu 26-01-17 21:34:04, Daniel Borkmann wrote:
[...]
> > > So to answer your second email with the bpf and netfilter hunks, why
> > > not replacing them with kvmalloc() and __GFP_NORETRY flag and add that
> > > big fat FIXME comment above there, saying explicitly that __GFP_NORETRY
> > > is not harmful though has only /partial/ effect right now and that full
> > > support needs to be implemented in future. That would still be better
> > > that not having it, imo, and the FIXME would make expectations clear
> > > to anyone reading that code.
> > 
> > Well, we can do that, I just would like to prevent from this (ab)use
> > if there is no _real_ and _sensible_ usecase for it. Having a real bug
> 
> Understandable.
> 
> > report or a fallback mechanism you are mentioning above would justify
> > the (ab)use IMHO. But that abuse would be documented properly and have a
> > real reason to exist. That sounds like a better approach to me.
> > 
> > But if you absolutely _insist_ I can change that.
> 
> Yeah, please do (with a big FIXME comment as mentioned), this originally
> came from a real bug report. Anyway, feel free to add my Acked-by then.

Thanks! I will repost the whole series today.

-- 
Michal Hocko
SUSE Labs