linux-kernel - Re: [tip:perf/core] x86/nmi: Push duration printk() to irq context

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]

Date:	Tue, 11 Feb 2014 08:44:22 -0800
From:	Dave Hansen <dave.hansen@...ux.intel.com>
To:	Peter Zijlstra <peterz@...radead.org>
CC:	mingo@...nel.org, hpa@...or.com, linux-kernel@...r.kernel.org,
	tglx@...utronix.de, dzickus@...hat.com,
	linux-tip-commits@...r.kernel.org
Subject: Re: [tip:perf/core] x86/nmi: Push duration printk() to irq context

On 02/11/2014 07:01 AM, Peter Zijlstra wrote:
> -	irq_work_queue(&perf_duration_work);
> +	if (!irq_work_queue(&perf_duration_work)) {
> +		early_printk("perf interrupt took too long (%lld > %lld), lowering "
> +			     "kernel.perf_event_max_sample_rate to %d\n",
> +			     avg_local_sample_len, allowed_ns >> 1,
> +			     sysctl_perf_event_sample_rate);
> +	}
>  }

That's a cool trick.  Works for me.
--
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/