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 5DE281CD1EE; Thu, 21 Nov 2024 11:54:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732190043; cv=none; b=H2NP316dOD7wA7LXcuxknWAHt1pyg2soV415FlwodjZ8VJtV6C4BoNFpBhKYhAzptlbySg7ascDrNK3GTNdnCIVcco8ktR2cueCCQ4o4cjNgWzgW1Zuy5424Slzll7BT64FApJxS4ReZsXxMSpc8ewdlZET2kxHik4HUS4WtcxM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732190043; c=relaxed/simple; bh=AmK0AI1qoNjZ0cH1lAwLtt6sWfdkbtQrIoeS241Raec=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=mhMJxmPS5rCTPZ731euklN91BZWZLnBYogRBq8/ILXmogwEuvZEH+PBdrnE5Amncl5nFdN2Ef978yB/ggwwyXMUA9Gp0DCo3jW15oxnR2UzKAKUOrMJpSM15khfOIMjNQVBKmCGL4H8Ev0dbUVfm1+CaouSYaqi8kFwjsUvPSjU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=i8kPc53J; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="i8kPc53J" 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=AmK0AI1qoNjZ0cH1lAwLtt6sWfdkbtQrIoeS241Raec=; b=i8kPc53JEweieYf82/XNWs+MyZ y4TdePE7L5rOgPuxlWUHzcVG6gzltYkmMsaE/ZzgBBynjqMwGiE+6yFLxQvITJvcH7YGqUYLkNaUo Qn0lvht+b2fv6Uq8UKqIZHgHfoTNAYjqbeJ1capS9O1WbedziHKV9DK7xsXuaA3Ta90tiAThMD8Ow IDMPeF/uK4/iX1VS8IQTC9idKd0O0yp9Co4xmqi+FU1LZtLHXRySZh8HVH6PkynqdkebIAQiuVifM ENg5RvdtXFb6WZIRurvGvEZHCyzs2oZ8tLHTrN29ItXiy8FUmXg9AVXM5eSe1PV5ZjVj9O4DrBFVX nIlPDXLw==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1tE5ku-00000006LDa-2iuE; Thu, 21 Nov 2024 11:53:54 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 83C1B30068B; Thu, 21 Nov 2024 12:53:53 +0100 (CET) Date: Thu, 21 Nov 2024 12:53:53 +0100 From: Peter Zijlstra To: Andrii Nakryiko Cc: Jiri Olsa , Oleg Nesterov , Andrii Nakryiko , bpf@vger.kernel.org, Song Liu , Yonghong Song , John Fastabend , Hao Luo , Steven Rostedt , Masami Hiramatsu , Alan Maguire , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, "H. Peter Anvin" Subject: Re: [RFC perf/core 05/11] uprobes: Add mapping for optimized uprobe trampolines Message-ID: <20241121115353.GJ24774@noisy.programming.kicks-ass.net> References: <20241105133405.2703607-1-jolsa@kernel.org> <20241105133405.2703607-6-jolsa@kernel.org> <20241105142327.GF10375@noisy.programming.kicks-ass.net> <20241119091348.GE11903@noisy.programming.kicks-ass.net> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Nov 20, 2024 at 04:07:38PM -0800, Andrii Nakryiko wrote: > USDTs are meant to be "transparent" to the surrounding code and they > don't mark any clobbered registers. Technically it could be added, but > I'm not a fan of this. Sure. Anyway, another thing to consider is FRED, will all of this still matter once that lands? If FRED gets us INT3 performance close to what SYSCALL has, then all this work will go unused.