From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) (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 414CF265CBB; Thu, 19 Jun 2025 08:47:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750322837; cv=none; b=be+hAeoVag1nHrV4Wigt/EC08plTjvb8ek1zW8cfsajKhz0lULe3xWpdmBgai3MgbNkv+FsLSQBRtQ1bRDS3G+djJC/8v9kpV7lsVSH/d1/f4IGtvANAF/W2ES2gQBGLGS20znBLMDiOe/BkEVTQ5QL0FxC1dWQr8H0eG6gsYXA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750322837; c=relaxed/simple; bh=b0XWpvGm8wgW6A/uSiwkYOT2KLb+DLRb+ve9xFGOjd8=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=hlD86U/aIWryqQnDblcvas44rqlOj3E0rG+fI8ocF5ICbDmCxKo5kvn2ZZWpS2OR2Niwkxf+EXXZFPk7C35m0HiW5JYnocb8z3sOMfDbzBYFia/2t3trJlBrhE4fcVZdY78ISjoP9GYiaXaGpjkkN7kL13FNUtBssSNY98agyjc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org; spf=pass smtp.mailfrom=goodmis.org; arc=none smtp.client-ip=216.40.44.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=goodmis.org Received: from omf05.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id B99241A075C; Thu, 19 Jun 2025 08:47:12 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf05.hostedemail.com (Postfix) with ESMTPA id D9D8C2000D; Thu, 19 Jun 2025 08:47:08 +0000 (UTC) Date: Thu, 19 Jun 2025 04:47:14 -0400 From: Steven Rostedt To: Peter Zijlstra Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, bpf@vger.kernel.org, x86@kernel.org, Masami Hiramatsu , Mathieu Desnoyers , Josh Poimboeuf , Ingo Molnar , Jiri Olsa , Namhyung Kim , Thomas Gleixner , Andrii Nakryiko , Indu Bhagat , "Jose E. Marchesi" , Beau Belgrave , Jens Remus , Linus Torvalds , Andrew Morton Subject: Re: [PATCH v10 05/14] unwind_user/deferred: Add unwind cache Message-ID: <20250619044714.5e676bf3@batman.local.home> In-Reply-To: <20250619075611.GX1613376@noisy.programming.kicks-ass.net> References: <20250611005421.144238328@goodmis.org> <20250611010428.603778772@goodmis.org> <20250618141345.GR1613376@noisy.programming.kicks-ass.net> <20250618113359.585b3770@gandalf.local.home> <20250619075611.GX1613376@noisy.programming.kicks-ass.net> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: D9D8C2000D X-Stat-Signature: hdnso6s7b8h14ty8pwta4y6t1z4ps3a6 X-Rspamd-Server: rspamout07 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX18mL5Mp+KUi7te2UfafbcE31pupD+cnzTg= X-HE-Tag: 1750322828-715024 X-HE-Meta: U2FsdGVkX1/6nmXO2xLOAzIpyS7FXKe4FiuacAkvz+FOe86TrNckB2C4V/DB0PqfuqCcIYSFlx7JIAKM8Sl1lCbwTmBopNN9hYbJhrGKJ5zwS8TG5y0SsSiybX4oYUoKi7R1VEG9MCmK1pnOdpwCAjSk0eObCETPMieQ2xZrRQVow61s0WfTp7bQye7vf9KsL2xFXydIb9H5q4GmlPLkjwbp9YAUOCpxoimMVgT/JuA03tf4+yQ51AIwY3pD7nI8eToHEESCgGFZljTyd6Scg1UoO07WBivLGtFmwzPTubHRHzJAav3GDewzhdMnDKrIwv+BjoYkx7qRFraknHjMtgibs3FafmEnOK8lUgMbFrK8R4fNj8SddH4rLYTGrv/c On Thu, 19 Jun 2025 09:56:11 +0200 Peter Zijlstra wrote: > Well, the trivial solution is to make it 511 and call it a day. Don't > make things complicated if you don't have to. I don't know if this is more complicated, but it should make it fit nicely in a page: /* Make the cache fit in a page */ #define UNWIND_MAX_ENTRIES \ ((PAGE_SIZE - sizeof(struct unwind_cache)) / sizeof(long)) -- Steve