From nobody Thu Dec 18 12:19:19 2025 Received: from mail-ot1-f44.google.com (mail-ot1-f44.google.com [209.85.210.44]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 30CDD17565 for ; Wed, 27 Mar 2024 04:50:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.44 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711515050; cv=none; b=mRpoa/do7sKCb5cgvitWt/RuTpU7xvubwqyW7zz9IQ4yd50T4L02GoL6g7NJXEQv0/zm67LjPojrYG4e/E1IA3qAYv3+9N6GCjB1pHjo4IT33k0m9/eZWM6uHQUJu/ZJUXwY+q2attUCS0QFD8cqfTE/FmuuYS14Ql+Ly+6ghZU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711515050; c=relaxed/simple; bh=ya97YfXpoRK/xYSjnVMkP8sXm9+Mh9TCgaVbVD32L2Y=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Jxmp1W/fJrYjummRNqhLBMiZ6AmMwLtdtBrbyhZCm5NNA+LJaeaN2SsNk+WU38JWDNgHwJTOfkQ72zansm4XAk5Q1ij6L44bIDbOTGXSeKkM5JghDVkgKMvyOKK/gkMi+q+YsQo/Ki2NP7reihJeKQzEYSDPPNsMM9/7LAlDStA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=sifive.com; spf=pass smtp.mailfrom=sifive.com; dkim=pass (2048-bit key) header.d=sifive.com header.i=@sifive.com header.b=nwXZug69; arc=none smtp.client-ip=209.85.210.44 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=sifive.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sifive.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sifive.com header.i=@sifive.com header.b="nwXZug69" Received: by mail-ot1-f44.google.com with SMTP id 46e09a7af769-6e67b5d6dd8so3499275a34.2 for ; Tue, 26 Mar 2024 21:50:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sifive.com; s=google; t=1711515048; x=1712119848; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=8r90DmKfTzo12+b9oHF/xBbsXVRSBOTytxxA308aMe8=; b=nwXZug69+IWYGlBdBnH+/S0tnz8xTjrFivzLBhkfZu916ZIO7k8frGmvIrXU6F2BEB TP7b3LdkOt7LhwjHG88NAsgbK7Eg4byv2iaCrOM2j1gXbiXT5d/hjq0oeG3+n8ySCUcw PRaMjJSsIolgo1DuhZI/p0RG+VCfaEe75TVpuBTJkDEDdQ5vl8sN60j3rDaCEtCq1sph IHM7ajqVmrmigUnMAkt88+9F/xhu1vul6dUp5Rjl5Pqgdt0Z3rtyZArpNT25fqDX6gI7 pVP2hDuBBSvnOobpHnjkORXkP7mSMiiqXLV7e9JMw46t0B4ou0VarDBYl53xrACdz2X5 Dy8w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1711515048; x=1712119848; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=8r90DmKfTzo12+b9oHF/xBbsXVRSBOTytxxA308aMe8=; b=g7gai5jqF5m4sEJiabBU8umyFK2lWIOAVudSkl+5OYq2kuo/8AuQIPBsQNFxwUrOXg rZQ9IX33CdPw0/zzPnM3uB1OEm75cfNWzCujxeB36uRSwyDBIPXzuJN6Om7I9BOyrEiT /db/YzvNRjJ1F+4UlRZCN4yMO7nFRRmrcnWoV8ED0oMou9g00EwGJYnUmd97qsOK4TAf O/ultPR+4hKeBAbKyyrc64plDkV/0Lc7MkcY9nO7BPdQLGpvVzYEbmu/ebo6xtMg36Xh zPdFJFd95LPy1OOv2gbKZSVtuQcyYBhQV2aku7YYNQhIfqJ0Vag+N6Ymwhq7hqiuWGYZ 9o1w== X-Gm-Message-State: AOJu0YyCS/D762bV8UEOsSi/metpt5jPv4msbVWf0mt911In6SNBfdW7 27L73H041F8LHMxt8fRIl4T6Q5i6/1WbEjmLMagjhGnlA9R7y2wnxLlf/zEOSEs= X-Google-Smtp-Source: AGHT+IE/gtW/a2EQvN+qhLpDTcQ1EZrF+9VNRUlZn60iPj1iarim6P+gGyjDapgmLmO07m/XYQ3rgg== X-Received: by 2002:a05:6830:1e72:b0:6e6:7db1:b444 with SMTP id m18-20020a0568301e7200b006e67db1b444mr154078otr.36.1711515048291; Tue, 26 Mar 2024 21:50:48 -0700 (PDT) Received: from sw06.internal.sifive.com ([4.53.31.132]) by smtp.gmail.com with ESMTPSA id e31-20020a63501f000000b005e4666261besm8351500pgb.50.2024.03.26.21.50.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 Mar 2024 21:50:47 -0700 (PDT) From: Samuel Holland To: Palmer Dabbelt , linux-riscv@lists.infradead.org Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Alexandre Ghiti , Jisheng Zhang , Yunhui Cui , Samuel Holland Subject: [PATCH v6 05/13] riscv: Only send remote fences when some other CPU is online Date: Tue, 26 Mar 2024 21:49:46 -0700 Message-ID: <20240327045035.368512-6-samuel.holland@sifive.com> X-Mailer: git-send-email 2.43.1 In-Reply-To: <20240327045035.368512-1-samuel.holland@sifive.com> References: <20240327045035.368512-1-samuel.holland@sifive.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" If no other CPU is online, a local cache or TLB flush is sufficient. These checks can be constant-folded when SMP is disabled. Signed-off-by: Samuel Holland Reviewed-by: Alexandre Ghiti --- (no changes since v4) Changes in v4: - New patch for v4 arch/riscv/mm/cacheflush.c | 4 +++- arch/riscv/mm/tlbflush.c | 4 +++- 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/riscv/mm/cacheflush.c b/arch/riscv/mm/cacheflush.c index d76fc73e594b..f5be1fec8191 100644 --- a/arch/riscv/mm/cacheflush.c +++ b/arch/riscv/mm/cacheflush.c @@ -21,7 +21,9 @@ void flush_icache_all(void) { local_flush_icache_all(); =20 - if (riscv_use_sbi_for_rfence()) + if (num_online_cpus() < 2) + return; + else if (riscv_use_sbi_for_rfence()) sbi_remote_fence_i(NULL); else on_each_cpu(ipi_remote_fence_i, NULL, 1); diff --git a/arch/riscv/mm/tlbflush.c b/arch/riscv/mm/tlbflush.c index da821315d43e..0901aa47b58f 100644 --- a/arch/riscv/mm/tlbflush.c +++ b/arch/riscv/mm/tlbflush.c @@ -79,7 +79,9 @@ static void __ipi_flush_tlb_all(void *info) =20 void flush_tlb_all(void) { - if (riscv_use_sbi_for_rfence()) + if (num_online_cpus() < 2) + local_flush_tlb_all(); + else if (riscv_use_sbi_for_rfence()) sbi_remote_sfence_vma_asid(NULL, 0, FLUSH_TLB_MAX_SIZE, FLUSH_TLB_NO_ASI= D); else on_each_cpu(__ipi_flush_tlb_all, NULL, 1); --=20 2.43.1