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Date:   Wed, 12 Apr 2023 08:31:42 -0700
From:   Christoph Hellwig <hch@infradead.org>
To:     David Howells <dhowells@redhat.com>
Cc:     netdev@vger.kernel.org, "David S. Miller" <davem@davemloft.net>,
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Subject: Re: [PATCH net-next v6 04/18] mm: Make the page_frag_cache allocator
 use per-cpu
Message-ID: <ZDbO3haK/1+7xdRC@infradead.org>
References: <20230411160902.4134381-1-dhowells@redhat.com>
 <20230411160902.4134381-5-dhowells@redhat.com>
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On Tue, Apr 11, 2023 at 05:08:48PM +0100, David Howells wrote:
> Make the page_frag_cache allocator have a separate allocation bucket for
> each cpu to avoid racing.  This means that no lock is required, other than
> preempt disablement, to allocate from it, though if a softirq wants to
> access it, then softirq disablement will need to be added.

Can you show any performance numbers?

> Make the NVMe, mediatek and GVE drivers pass in NULL to page_frag_cache()
> and use the default allocation buckets rather than defining their own.

Let me ask a third time as I've not got an answer the last two times:
why are these callers treated different from the others?