From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9B85BC3DA6D for ; Tue, 20 May 2025 14:07:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=9/xYMuJvlYqKg9T8+4FvlvemlbEjveAqHRjitcUsup8=; b=OW7zV8yQo4ETJCqSwsVnKlKiuV 2OAm0FabZZ/tvGdeEWkhGiyndD6AC/fAItyy/OM/ZZ6jjM9xTJ7o131o7Gz4XHrATalGisnSK0e26 7SpLY6/9m1N41BNEnsh4yC0d7M7B6zw/QiEQUhyk45di6oDezz0FKyc8hpJbGjHYY2vYvTocyNOCO ymp0vXMMYL+zNpJJ+gfa3LTUQp9GVGrhDvP/HN5Ikw3LvlqUBPSSdsganaclnlXTUPcP5WVqP6TrC UP1LMJnWC+CyY63kfMjp/VabdccqH1Co/b+2k5gVzz4yM2zLrpM4s6UvOeXUipZd8flXjQQ1OX7gS /wu6I3dA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uHNcc-0000000D6jA-3X5X; Tue, 20 May 2025 14:07:10 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uHNaW-0000000D6PA-1UUW for linux-arm-kernel@lists.infradead.org; Tue, 20 May 2025 14:05:01 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 7082C5C561E; Tue, 20 May 2025 14:02:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C3917C4CEE9; Tue, 20 May 2025 14:04:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1747749899; bh=FwTN2M9DsTfsj/6tueLnbl1Llxw38v4QaqUMi15NmgA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ES8SmexGvRqYBgMtzkBjOvrX8znCoPDidI0UZGzvGoeB4LDg48e4Pbi61iBWLDs+l vRwHMbBZr1dj9zKsF5t4lC+VmR7XYkv8nUYzycpmwY/LPtxMxPFPU5kmSKLGKE+ytf j/JYY/cXGPY2bd1DHz64piyGl6OT5jutJn9/54pWOyvUPGsY7rZ69SbkR+ICbTq9X6 YjQ3Ouo8oynmSUZlaTNCgBUIKWPJLzcf74ZCRQYXrlif7xBV0Sw1+17+s+XCdltnw7 1j2u3nI01jk9hQr0RxXck0JNmHTvm2RH3fy5aZBp6UwDQ2a6hsFmHL107VvNuyiP6p whQD/WTNnDIcQ== Date: Tue, 20 May 2025 15:04:54 +0100 From: Will Deacon To: Steven Rostedt Cc: Nam Cao , Gabriele Monaco , linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org, john.ogness@linutronix.de, Catalin Marinas , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v6 17/22] arm64: mm: Add page fault trace points Message-ID: <20250520140453.GA18711@willie-the-truck> References: <554038c996662282df8a9d0482ef06f8d44fccc5.1745999587.git.namcao@linutronix.de> <20250516140449.GB13612@willie-the-truck> <3E29A42D-8A6A-4342-8C60-2BEF1EDCD640@goodmis.org> <20250519151238.GB17177@willie-the-truck> <20250519120837.794f6738@batman.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250519120837.794f6738@batman.local.home> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250520_070500_438279_B9C53156 X-CRM114-Status: GOOD ( 21.14 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, May 19, 2025 at 12:08:37PM -0400, Steven Rostedt wrote: > On Mon, 19 May 2025 16:12:39 +0100 > Will Deacon wrote: > > > > Perf events work for perf only. My question is why isn't this a tracepoint > > > that perf could hook into? > > > > Well, the perf event came first in this case, so we're stuck with it :/ > > I wonder what effort it will take to convert perf events to tracepoints ;-) > > Note, I'm talking about tracepoints and not trace events, where the > latter is exposed to tracefs and the former is not. > > > > > I was hoping we could settle for a generic helper that could emit both > > the trace event and the perf event (so that the ordering of the two is > > portable across architectures) but, judging by Nam's reply, the trace > > event is needed before kprobes gets a look in. > > Perhaps we could add a helper function that does both (perf and > tracepoint) and hide the implementation from the code that calls it? Something like that sounds like a good idea, yes. > But I'm currently still on PTO so I haven't looked at the details yet. Enjoy! Will