linux-kernel - Re: [RFC PATCH] bpf: Add new bpf map type for timer

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] [day] [month] [year] [list]

Message-ID: <5627ED3D.5080004@plumgrid.com>
Date:	Wed, 21 Oct 2015 12:53:33 -0700
From:	Alexei Starovoitov <ast@...mgrid.com>
To:	He Kuang <hekuang@...wei.com>, ast@...nel.org, davem@...emloft.net,
	daniel@...earbox.net, mingo@...nel.org, rostedt@...dmis.org,
	xiakaixu@...wei.com
Cc:	wangnan0@...wei.com, linux-kernel@...r.kernel.org
Subject: Re: [RFC PATCH] bpf: Add new bpf map type for timer

On 10/21/15 3:02 AM, He Kuang wrote:
> Here's a hypothetical scenario to illustrate the use of timer map.
>
> A video frame is updated between frame_refresh_start() and
> frame_refresh_end(), in most cases, the interval between these two
> functions is less than 40ms, but occasionally over 200ms.
>
> We can set a timer which alarm after the frame_refresh_start() has
> been executed 42ms(slightly larger than 40ms) and destory this timer
> if frame_refresh_end() is called. So, for most cases, the timer is not
> triggered, this can significantly reduce the amount of trace data.

As a feature it sounds useful, but implementation is not acceptable.
You cannot have one callback stub for all users of this feature.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/