From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A78EE182C0 for ; Mon, 12 Jun 2023 09:44:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=Vha0HB5ydDcFbo3VCXSefJuuYWl20O+Nf7SIjJnvNeQ=; b=q1ZhBNP4qtxvbPwK8aS05ujFQK xkM1wyeTQ3b2tZfRkV6hzlRZLK2WCGWfzpzCn0wRiyJp3H7Ts9sjYOFCVde3ips/4fuum90PHqinO M38u6Ix5kvN1NYw8MkjBKBg2+hDEKrSSqPFddzyiLZmm63pXYCHOQqlkWJ1x67nr63HMjP3xykqRI sU7A3JHj+KtHBxXqhTxhw/430RbtLdz8rGeY7oU3d3OTMSkeZtMe9Bh3MiZ2fpE2LmF32kHmPUqp6 jTsZdSu59Ry/uDg82NmOZMdQc1qk1q20Ovujft5ZSpk/lJMrSV9h/0CWK+4BJj1j+9sOHvchklMjl WkMUbwYw==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1q8e5h-002Oik-UG; Mon, 12 Jun 2023 09:44:02 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 0AE743002A9; Mon, 12 Jun 2023 11:44:01 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id E658121473307; Mon, 12 Jun 2023 11:44:00 +0200 (CEST) Date: Mon, 12 Jun 2023 11:44:00 +0200 From: Peter Zijlstra To: torvalds@linux-foundation.org, keescook@chromium.org, gregkh@linuxfoundation.org, pbonzini@redhat.com Cc: masahiroy@kernel.org, nathan@kernel.org, ndesaulniers@google.com, nicolas@fjasle.eu, catalin.marinas@arm.com, will@kernel.org, vkoul@kernel.org, trix@redhat.com, ojeda@kernel.org, mingo@redhat.com, longman@redhat.com, boqun.feng@gmail.com, dennis@kernel.org, tj@kernel.org, cl@linux.com, acme@kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, namhyung@kernel.org, irogers@google.com, adrian.hunter@intel.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, paulmck@kernel.org, frederic@kernel.org, quic_neeraju@quicinc.com, joel@joelfernandes.org, josh@joshtriplett.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, rientjes@google.com, vbabka@suse.cz, roman.gushchin@linux.dev, 42.hyeyoo@gmail.com, apw@canonical.com, joe@perches.com, dwaipayanray1@gmail.com, lukas.bulwahn@gmail.com, john.johansen@canonical.com, paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org, llvm@lists.linux.dev, linux-perf-users@vger.kernel.org, rcu@vger.kernel.org, linux-security-module@vger.kernel.org, tglx@linutronix.de, ravi.bangoria@amd.com, error27@gmail.com, luc.vanoostenryck@gmail.com Subject: Re: [PATCH v3 46/57] perf: Simplify pmu_dev_alloc() Message-ID: <20230612094400.GG4253@hirez.programming.kicks-ass.net> References: <20230612090713.652690195@infradead.org> <20230612093540.850386350@infradead.org> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230612093540.850386350@infradead.org> On Mon, Jun 12, 2023 at 11:07:59AM +0200, Peter Zijlstra wrote: > > Signed-off-by: Peter Zijlstra (Intel) > --- > kernel/events/core.c | 65 ++++++++++++++++++++++++--------------------------- > 1 file changed, 31 insertions(+), 34 deletions(-) > > --- a/kernel/events/core.c > +++ b/kernel/events/core.c > @@ -11285,49 +11285,46 @@ static void pmu_dev_release(struct devic > > static int pmu_dev_alloc(struct pmu *pmu) > { > + int ret; > > + struct device *dev __free(put_device) = > + kzalloc(sizeof(struct device), GFP_KERNEL); > + if (!dev) > + return -ENOMEM; > > + dev->groups = pmu->attr_groups; > + device_initialize(dev); > > + dev_set_drvdata(dev, pmu); > + dev->bus = &pmu_bus; > + dev->release = pmu_dev_release; > > + ret = dev_set_name(dev, "%s", pmu->name); > if (ret) > + return ret; > > + ret = device_add(dev); > if (ret) > + return ret; > > + struct device *del __free(device_del) = dev; Greg, I'm not much familiar with the whole device model, but it seems unfortunate to me that one has to call device_del() explicitly if we already have a put_device() queued. Is there a saner way to write this? > > + /* For PMUs with address filters, throw in an extra attribute: */ > + if (pmu->nr_addr_filters) { > + ret = device_create_file(dev, &dev_attr_nr_addr_filters); > + if (ret) > + return ret; > + } > + > + if (pmu->attr_update) { > + ret = sysfs_update_groups(&dev->kobj, pmu->attr_update); > + if (ret) > + return ret; > + } > + > + no_free_ptr(del); > + pmu->dev = no_free_ptr(dev); > + return 0; > }