Received: by 2002:ab2:6816:0:b0:1f9:5764:f03e with SMTP id t22csp3204924lqo; Tue, 21 May 2024 09:36:25 -0700 (PDT) X-Forwarded-Encrypted: i=2; AJvYcCVrSKkPdodV8uUT1BcuuRJqu7OYK3SwxZXrhxJjg+6bKtBXB0zhI1mPzJtsmmvUSlijW4FckIGrHfYApLLYyzEnOKqEKZcLe+rDJzAxvg== X-Google-Smtp-Source: AGHT+IGX2jyuYnWvyMFNE/a/W2Jr17F64dlUeMkRxmU1Ty04LfASOlUHhB+ocXosOOlgD//qsUws X-Received: by 2002:a05:6a20:734f:b0:1af:e624:b9b2 with SMTP id adf61e73a8af0-1afe624ba5emr30914980637.19.1716309385045; Tue, 21 May 2024 09:36:25 -0700 (PDT) Return-Path: Received: from sy.mirrors.kernel.org (sy.mirrors.kernel.org. [2604:1380:40f1:3f00::1]) by mx.google.com with ESMTPS id 41be03b00d2f7-658905b5ee0si4446056a12.409.2024.05.21.09.36.24 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 21 May 2024 09:36:25 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel+bounces-185221-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:40f1:3f00::1 as permitted sender) client-ip=2604:1380:40f1:3f00::1; Authentication-Results: mx.google.com; dkim=neutral (body hash did not verify) header.i=@kernel.org header.s=k20201202 header.b=OSnDxMBv; arc=fail (body hash mismatch); spf=pass (google.com: domain of linux-kernel+bounces-185221-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:40f1:3f00::1 as permitted sender) smtp.mailfrom="linux-kernel+bounces-185221-linux.lists.archive=gmail.com@vger.kernel.org"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sy.mirrors.kernel.org (Postfix) with ESMTPS id 057B1B21768 for ; Tue, 21 May 2024 16:36:11 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id CB00E147C72; Tue, 21 May 2024 16:35:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="OSnDxMBv" 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 E9EB317556; Tue, 21 May 2024 16:35:42 +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=1716309343; cv=none; b=WturC9cT0KHHwLtlK3h311sv13E4PLUxXpaYQtwF2lXl5wxydbYxaD00d5bL3EUnXM5jUwVxNdQv8YK9nV+m3mCVCHNwSuyv9i35Ptfs3JDiHMhhKcF5Ps7bNxh/zjZknHKlyToPjeMcATE6qxR7mbxxuqzZvDk2lxEBrMklcIs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716309343; c=relaxed/simple; bh=flYhV7d20dQSVWKKG9xe6WN4b57IFP0PEYtYsZvhEgI=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=TdeJ6eJqRIG2wKSZWLJctcfPWASXSr3cO29sHfWic51GwnWOJ6OCN6WM/7qHfVnnvfoEilLoxjYLX3GnPzIE9CN2tk3YKrKtkdXMD2gw8OgJTpUcvaEDMYRSvPckYAE3EfznH5cVPdFGn9+OtnBIBUP7VJc6grXG2IrWs/lXyNk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OSnDxMBv; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id BFA2AC2BD11; Tue, 21 May 2024 16:35:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1716309342; bh=flYhV7d20dQSVWKKG9xe6WN4b57IFP0PEYtYsZvhEgI=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=OSnDxMBvwuZmzw1tj9S4tW3PKxmd2QDDX5Hs9M+GREWOOeCuYO8A2o5lxdeMgcrBP HgpjrRpH2Fv2a9TgqbPZcKVK4ubavEPLcA2O0fHaLwzzIt6FohK6rbPtUmFiHRzZQ+ usIGPMVbj6Qg/P/fxj5GiHm/xqj0oa1XGLBu6bxhuTELspa5Cg+ZXtgLVzXogmv2el 5ohMQn2jiBrQTrk3P3s+/iX30+ZHyw+rFS3LLuM17nzzD+reEO+uUyW9rI6Mps3R/r nqtw9VqHOkG5XbMGosKQIYPtq3aKMxk4wwsKQwQxE7YyNLyD2lvSD+2MlDm6L+yrVk O4wvpONO9IlYw== From: =?utf-8?B?QmrDtnJuIFTDtnBlbA==?= To: Xiao Wang , paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, luke.r.nels@gmail.com, xi.wang@gmail.com Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, eddyz87@gmail.com, song@kernel.org, yonghong.song@linux.dev, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, pulehui@huawei.com, haicheng.li@intel.com, Xiao Wang Subject: Re: [PATCH] riscv, bpf: try RVC for reg move within BPF_CMPXCHG JIT In-Reply-To: <20240519050507.2217791-1-xiao.w.wang@intel.com> References: <20240519050507.2217791-1-xiao.w.wang@intel.com> Date: Tue, 21 May 2024 18:35:39 +0200 Message-ID: <87a5kjdsx0.fsf@all.your.base.are.belong.to.us> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Xiao Wang writes: > We could try to emit compressed insn for reg move operation during CMPXCHG > JIT, the instruction compression has no impact on the jump offsets of > following forward and backward jump instructions. ..and at some point we should start supporting Zacas and friends, instead of lr/sc. > Signed-off-by: Xiao Wang Acked-by: Bj=C3=B6rn T=C3=B6pel