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Date: Wed, 5 Aug 2015 17:18:57 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>, linux-kernel@vger.kernel.org,
        adrian.hunter@intel.com, Arnaldo Carvalho de Melo <acme@infradead.org>,
        Vince Weaver <vince@deater.net>, Stephane Eranian <eranian@google.com>
Subject: Re: [PATCH RFC v1 1/4] perf: Introduce extended syscall error
 reporting
Message-ID: <20150805151857.GL19282@twins.programming.kicks-ass.net>
References: <1437738359-23920-1-git-send-email-alexander.shishkin@linux.intel.com>
 <1437738359-23920-2-git-send-email-alexander.shishkin@linux.intel.com>
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On Fri, Jul 24, 2015 at 02:45:56PM +0300, Alexander Shishkin wrote:
> +/*
> + * Use part of the [-1, -MAX_ERRNO] errno range for perf's extended error
> + * reporting. Anything within [-PERF_ERRNO, -MAX_ERRNO] is an index of a
> + * perf_err_site structure within __perf_err section. 3.5k should be enough
> + * for everybody, but let's add a boot-time warning just in case it overflows
> + * one day.
> + */
> +#define PERF_ERRNO 512

linux/errno.h has 512-529 in use, so this range overlaps with 'normal'
errno values.