From: David Miller <davem@davemloft.net>
To: alexander.duyck@gmail.com
Cc: netdev@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, jannh@google.com
Subject: Re: [net PATCH 0/2] Address recent issues found in netdev page_frag_alloc usage
Date: Sun, 17 Feb 2019 15:50:26 -0800 (PST) [thread overview]
Message-ID: <20190217.155026.2230689002634375366.davem@davemloft.net> (raw)
In-Reply-To: <20190215223741.16881.84864.stgit@localhost.localdomain>
From: Alexander Duyck <alexander.duyck@gmail.com>
Date: Fri, 15 Feb 2019 14:44:05 -0800
> This patch set addresses a couple of issues that I had pointed out to Jann
> Horn in response to a recent patch submission.
>
> The first issue is that I wanted to avoid the need to read/modify/write the
> size value in order to generate the value for pagecnt_bias. Instead we can
> just use a fixed constant which reduces the need for memory read operations
> and the overall number of instructions to update the pagecnt bias values.
>
> The other, and more important issue is, that apparently we were letting tun
> access the napi_alloc_cache indirectly through netdev_alloc_frag and as a
> result letting it create unaligned accesses via unaligned allocations. In
> order to prevent this I have added a call to SKB_DATA_ALIGN for the fragsz
> field so that we will keep the offset in the napi_alloc_cache
> SMP_CACHE_BYTES aligned.
Series applied, thanks Alexander.
prev parent reply other threads:[~2019-02-17 23:50 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-15 22:44 [net PATCH 0/2] Address recent issues found in netdev page_frag_alloc usage Alexander Duyck
2019-02-15 22:44 ` [net PATCH 1/2] mm: Use fixed constant in page_frag_alloc instead of size + 1 Alexander Duyck
2023-02-17 9:30 ` Vlastimil Babka
2023-03-20 15:14 ` Vlastimil Babka
2019-02-15 22:44 ` [net PATCH 2/2] net: Do not allocate page fragments that are not skb aligned Alexander Duyck
2019-02-17 23:50 ` David Miller [this message]
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