Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Mon, 5 Jun 2023 11:34:00 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Mark Rutland <mark.rutland@arm.com>
Cc:     Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        Ravi Bangoria <ravi.bangoria@amd.com>, jolsa@kernel.org,
        irogers@google.com, bp@alien8.de, adrian.hunter@intel.com,
        linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
        "linux-samsung-soc@vger.kernel.org" 
        <linux-samsung-soc@vger.kernel.org>,
        "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>,
        "regressions@lists.linux.dev" <regressions@lists.linux.dev>
Subject: Re: [REGRESSION][BISECT] perf/core: Remove pmu linear searching code
Message-ID: <20230605093400.GK38236@hirez.programming.kicks-ass.net>
References: <3abd3693-ad87-9abf-a762-337076638fcc@linaro.org>
 <ZH2KVyyC5oMr+Vk2@FVFF77S0Q05N>
 <20230605092731.GZ4253@hirez.programming.kicks-ass.net>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20230605092731.GZ4253@hirez.programming.kicks-ass.net>
Precedence: bulk

On Mon, Jun 05, 2023 at 11:27:31AM +0200, Peter Zijlstra wrote:
> On Mon, Jun 05, 2023 at 08:10:15AM +0100, Mark Rutland wrote:
> 
> > How does this work on x86? Do you have pseudo-PMUs for PERF_TYPE_HARDWARE and
> > PERF_TYPE_RAW ?
> 
> Generic code maps TYPE_HARDWARE and TYPE_HW_CACHE to TYPE_RAW for a
> first go, only if that fails it will try the actual type.
> 
> And x86 has the (first) CPU PMU has TYPE_RAW, on hybrid, it will
> transparently pick the right actual PMU.

Oh, I might've misread that last bit.. TYPE_RAW is always the big core,
it will not magic the thing. If you want little events you gotta
manually find the little pmu.