From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 219591FA245; Mon, 21 Oct 2024 14:58:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729522739; cv=none; b=lN8VJ3gNkCiXlq1Oacu6+3LM4w8jF51f7Tetiwq5WZ4EQE8mHDglxGo/7uO4+k5Zo3kUhOHmehEkT+n6VBWuqNDqjJymBC0doXT3DDakkYN9E0IxiPSUnL0U4jgXiHQ5sDYiotDoYDwYbcIi+bfnpMnPqNztXpxBGWQDPMhLYyY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729522739; c=relaxed/simple; bh=YZVFt6Fiq3Uw/uK9i5TolLo/2N8dCMVm8nklxxHdVSk=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=P7DZplQtjzCZIq7jgTAHMQDE/7Bf32mBiKAe9e8Vp3NOwHmmSNQA2AuojRTthGKg/cwXxKyfQVnC1bZivxbiLEEDfrqk6jObcl5vM0sNpYze7C8FXfDHW2c8VmvrDU/PAfrY0qMsFcYgcu7PjmlK2dq66ekDr4sQXoxGMvKKY3Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=rUcsqbhj; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="rUcsqbhj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B60A4C4CECD; Mon, 21 Oct 2024 14:58:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729522738; bh=YZVFt6Fiq3Uw/uK9i5TolLo/2N8dCMVm8nklxxHdVSk=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=rUcsqbhjNMYRkQhi9IaLVRmqeZBOtm8RBVcgBKhELkrrMB8bJGsA2bYDCGkxgITty lp9o/8LZo7BG0RXZXYJLgh+muhFAKxeibcxuqVfG3JcLRP/vaTOWnsQD+6eCou7iQ4 KIo7pX0L1vjulzn7Vd0srSt4T+Jt+FPkRFzFtm980iT6lPkpoXhoRj+EVrPMshfElv cqBEB2nZ0D59Aw8BTfrtITTkfDSQUR42eICVwBkvvij5rTEGo46xrLnx3zk9dblBQH 0eXvnb7LQnG5K19XINvYXmY3NvGv8IPCy3Zv4DBS22PACtfbeBRNLHSozp4PHU+z9V dehnd5OvjlMDg== Date: Mon, 21 Oct 2024 23:58:54 +0900 From: Masami Hiramatsu (Google) To: Steven Rostedt Cc: LKML , Linux trace kernel , Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Ryan Roberts Subject: Re: [PATCH] fgraph: Separate size of ret_stack from PAGE_SIZE Message-Id: <20241021235854.8d287463ee68d4c4c2846b29@kernel.org> In-Reply-To: <20241019152951.053f9646@rorschach.local.home> References: <20241019152951.053f9646@rorschach.local.home> X-Mailer: Sylpheed 3.8.0beta1 (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 On Sat, 19 Oct 2024 15:29:51 -0400 Steven Rostedt wrote: > From: Steven Rostedt > > The ret_stack (shadow stack used by function graph infrastructure) is > currently defined as PAGE_SIZE. But some architectures which have 64K > PAGE_SIZE, this is way overkill. Also there's an effort to allow the > PAGE_SIZE to be defined at boot up. > > Hard code it for now to 4096. In the future, this size may change and even > be dependent on specific architectures. > > Link: https://lore.kernel.org/all/e5067bb8-0fcd-4739-9bca-0e872037d5a1@arm.com/ > Looks good to me. Acked-by: Masami Hiramatsu (Google) Thanks! > Suggested-by: Ryan Roberts > Signed-off-by: Steven Rostedt (Google) > --- > kernel/trace/fgraph.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c > index ee829d65f301..51e81b299a0d 100644 > --- a/kernel/trace/fgraph.c > +++ b/kernel/trace/fgraph.c > @@ -153,7 +153,7 @@ enum { > * SHADOW_STACK_OFFSET: The size in long words of the shadow stack > * SHADOW_STACK_MAX_OFFSET: The max offset of the stack for a new frame to be added > */ > -#define SHADOW_STACK_SIZE (PAGE_SIZE) > +#define SHADOW_STACK_SIZE (4096) > #define SHADOW_STACK_OFFSET (SHADOW_STACK_SIZE / sizeof(long)) > /* Leave on a buffer at the end */ > #define SHADOW_STACK_MAX_OFFSET \ > -- > 2.45.2 > -- Masami Hiramatsu (Google)