From: Dennis Zhou <dennisszhou@gmail.com>
To: Tejun Heo <tj@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>,
davem@davemloft.net, ast@kernel.org, john.fastabend@gmail.com,
mark.rutland@arm.com, richard@nod.at, sp3485@columbia.edu,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH net 0/3] Fix for BPF devmap percpu allocation splat
Date: Wed, 18 Oct 2017 16:45:08 -0500 [thread overview]
Message-ID: <20171018214508.GA12295@localhost.corp.microsoft.com> (raw)
In-Reply-To: <20171018132526.GC1302522@devbig577.frc2.facebook.com>
Hi Daniel and Tejun,
On Wed, Oct 18, 2017 at 06:25:26AM -0700, Tejun Heo wrote:
> > Daniel Borkmann (3):
> > mm, percpu: add support for __GFP_NOWARN flag
>
> This looks fine.
>
Looks good to me too.
> > bpf: fix splat for illegal devmap percpu allocation
> > bpf: do not test for PCPU_MIN_UNIT_SIZE before percpu allocations
>
> These look okay too but if it helps percpu allocator can expose the
> maximum size / alignment supported to take out the guessing game too.
>
I can add this once we've addressed the below if we want to.
> Also, the reason why PCPU_MIN_UNIT_SIZE is what it is is because
> nobody needed anything bigger. Increasing the size doesn't really
> cost much at least on 64bit archs. Is that something we want to be
> considering?
>
I'm not sure I see the reason we can't match the minimum allocation size
with the unit size? It seems weird to arbitrate the maximum allocation
size given a lower bound on the unit size.
Thanks,
Dennis
next prev parent reply other threads:[~2017-10-18 21:45 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-17 14:55 [PATCH net 0/3] Fix for BPF devmap percpu allocation splat Daniel Borkmann
2017-10-17 14:55 ` [PATCH net 1/3] mm, percpu: add support for __GFP_NOWARN flag Daniel Borkmann
2017-10-17 15:53 ` Alexei Starovoitov
2017-10-17 14:55 ` [PATCH net 2/3] bpf: fix splat for illegal devmap percpu allocation Daniel Borkmann
2017-10-17 15:54 ` Alexei Starovoitov
2017-10-17 16:28 ` John Fastabend
2017-10-17 14:55 ` [PATCH net 3/3] bpf: do not test for PCPU_MIN_UNIT_SIZE before percpu allocations Daniel Borkmann
2017-10-17 15:55 ` Alexei Starovoitov
2017-10-17 16:29 ` John Fastabend
2017-10-17 15:03 ` [PATCH net 0/3] Fix for BPF devmap percpu allocation splat David Laight
2017-10-17 15:11 ` Daniel Borkmann
2017-10-18 13:25 ` Tejun Heo
2017-10-18 14:03 ` Daniel Borkmann
2017-10-18 14:22 ` Daniel Borkmann
2017-10-18 15:28 ` Alexei Starovoitov
2017-10-18 15:31 ` Daniel Borkmann
2017-10-18 21:45 ` Dennis Zhou [this message]
2017-10-21 16:00 ` Tejun Heo
2017-10-19 12:14 ` David Miller
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