netdev - Re: [PATCH 5/6] bpf: hash: avoid to call kmalloc() in eBPF prog

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

Message-ID: <5670A577.3010207@iogearbox.net>
Date:	Wed, 16 Dec 2015 00:42:47 +0100
From:	Daniel Borkmann <daniel@...earbox.net>
To:	Alexei Starovoitov <alexei.starovoitov@...il.com>,
	Ming Lei <tom.leiming@...il.com>
CC:	linux-kernel@...r.kernel.org, Alexei Starovoitov <ast@...nel.org>,
	"David S. Miller" <davem@...emloft.net>, netdev@...r.kernel.org
Subject: Re: [PATCH 5/6] bpf: hash: avoid to call kmalloc() in eBPF prog

On 12/16/2015 12:10 AM, Alexei Starovoitov wrote:
...
> this rounding to cache line is great for performance, but it's extra
> memory upfront which may not be needed. The per-allocation is a classic
> performance vs memory trade-off. In other cases it may hurt.
> So could you change the patch to do pre-allocation only when
> requested by user space via extra flag for hash map or via
> new BPF_MAP_TYPE_HASH_PREALLOC type? Not sure yet whether flag or
> new type is better. I guess implementation will dictate.

Was also thinking about this, probably new map type makes sense.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html