From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) (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 C3A3D236457 for ; Mon, 15 Sep 2025 16:06:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.15 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757952413; cv=none; b=q/S7zVps+g/nUhP+beKLkGA0h4JCKdOd8el8B+XH+uDLWtR1/cmGGxymBRGzoDYS4gIIR7BspejJp3jTnuhu1EGhVDNsegRkTNRC3eUPHFn4RHSFsejUWa2fEE8zcNuoJxfOZPGXcQW6ktNsPQINEyDtCeRYUdkRYdBTEauWAq4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757952413; c=relaxed/simple; bh=fcxZ57H+d+girPPBmyC75isL2Wiz5HSqYhjex9Y00Nc=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Em8pAC6t/Wro6kVkbV8AHU7Hq6QHjnz3l6uW30ydxjuLe/Ua/CZOz2CdsuZPDTSnDWOPx7zCMJ1ayCGEnQsSbT1EdHXZ/9eFXNwCbzG7/M6iXBUM4UY0zhQ8BKuLeAh0pAosY4yXQe1F9LMNzLIugGeqN6EAu+3uEQqjXSqXGmY= 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=216.40.44.15 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 omf14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 7694FC068C; Mon, 15 Sep 2025 16:06:43 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf14.hostedemail.com (Postfix) with ESMTPA id 105C42D; Mon, 15 Sep 2025 16:06:40 +0000 (UTC) Date: Mon, 15 Sep 2025 12:07:42 -0400 From: Steven Rostedt To: Indu Bhagat Cc: Jan Beulich , Rainer Orth , "linux-toolchains@vger.kernel.org" , Jens Remus , Sterling Augustine , Pavel Labath , Andrii Nakryiko , Josh Poimboeuf , Serhei Makarov , Binutils Subject: Re: Unaligned access trade-offs for SFrame FRE layout Message-ID: <20250915120742.7ff2f781@gandalf.local.home> In-Reply-To: <76b8c89e-5d80-48da-aff1-580d539d1b87@oracle.com> References: <9d104c46-855c-4b36-8226-1f59b59e455c@suse.com> <26895e7a-5d54-4c89-aeb4-bcd094ba081d@suse.com> <1308e9fa-90c8-4c52-b53d-afd24542b4c8@suse.com> <76b8c89e-5d80-48da-aff1-580d539d1b87@oracle.com> X-Mailer: Claws Mail 3.20.0git84 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-toolchains@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-Stat-Signature: ezna6ioscrdi9pkikp1un4hj1c4mmrbp X-Rspamd-Server: rspamout03 X-Rspamd-Queue-Id: 105C42D X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX196+SOoQl6afTaee45iaSZiNI1+w2v55WM= X-HE-Tag: 1757952400-919925 X-HE-Meta: U2FsdGVkX1/VT/GMryl4Uu2bzW8mpGa+eeyJCJ2FAf5Q4D3p8gSm5w/oiYl/s9O658F9Rq4TCjILu2IV2e2Yq/ZAqG6efuhmA06H8xUUG+MAsz9ryiGqHomGsXwvU14sl8ocZ3b6xf956TG/D7KM8rvIXYKfpSpsyo1intnd7Ie+44unBmzq/w5+KGr2Qb/Q8NaSFrV0gAjeb8Mp3a0f+TbC0zGvwLswKw/Hn4mgk+bDcUrZ8H4/sxFPuNhig8Axr0i3USQ6Kmn+uSnc5cwdHmNDDprfW0feUus0mE23bkQ9N+m6GYruooZ6tvRhBrd20skk+U68cOtNIpRyPNz6qG2DsliNYccFBXhyInEmT1folT1MbV2+Fw== On Sun, 14 Sep 2025 22:42:46 -0700 Indu Bhagat wrote: > In such cases, the routines reading the SFrame data under consideration > here (SFrame FRE start addr, and SFrame FRE stack offsets) from memory > will need to use a memcpy to copy out the data to an aligned location. > > In GNU Binutils libsframe (used by ld), we do the above. Such a "SFrame > FRE decoding" routine could be provided in a arch-specific manner in > SFrame stack tracers. I'm perfectly fine with making it a requirement for the reader of the SFrame section having to use memcpy into an aligned structure for reading if the architecture requires it. Let only the architectures that have issues with unaligned access take the performance hit. -- Steve