From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yw1-f171.google.com (mail-yw1-f171.google.com [209.85.128.171]) (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 ED8C643F8A5 for ; Tue, 1 Sep 2026 15:51:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788277900; cv=none; b=cCOeSZx5tN0Td854DkhXU0KN6Xqj1a87eQxebUp/2z5nVo9XWRuLuXnteePeXqQWeOoNBFiafv0VDtjoWb6E3wQt7Zf11beYTke+pIl/uIhtN61XtatW9Gsq3YhPC/PaZlX/2Qijt4/Y7hR9YSrAYZytXtpMnE44WHYplLxWL54= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788277900; c=relaxed/simple; bh=hdl+OTB1yVSH9JDm9Gsa4MpjZfNwEkwTNc5VP4tp/Q8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NY//FN/iiRyDxIQQVqfxkysP6R8GaB+Z3WfKScc/k9XUB2h7q/bKspRcopL/qMN9K+5NTicIaXOfsj4aytNkJ8BbQJVcw8csxjLCFIa+buS6FXFTxXvoxBwrCGdKFm8k1ByiyRcGfpr5I+bHNAatC+Fq3rNFACLLEvKTqLyeK+8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Em+ZiQgd; arc=none smtp.client-ip=209.85.128.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Em+ZiQgd" Received: by mail-yw1-f171.google.com with SMTP id 00721157ae682-865bdc6ed72so1113207b3.2 for ; Tue, 01 Sep 2026 08:51:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1788277898; x=1788882698; 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:content-type; bh=usbV3+3pOtvfEBv9PQmV+IQ3z+lbp/nmOaEabXXhASE=; b=Em+ZiQgdH8evZL7lECXfuy5yQ9F6kyaJ/nTw0djSb/HyRGDyy6o16sBnQj6uIzPdU6 T1BFu/p81atYbHHZ4h9cpyc6ny9X17cycgkgjWZXCn4ZbE36nuD6/nZbu4bSW7L+Q+S8 JVpvyJmmawIDXiIN3y15j10c46ZJWlA5Me53u5z6VxBM94ps6z1/rUzKLXUOdUIozAbT yhzFtg4J923v7BVi5QklD6dCGiq8dPrx1z9YQPXITc5wZZ7rMmb/XM6Oj3sFWNDYGly3 JLbopQ69VBqfLGx0M29JnIJzJBaKJwG2ChTc9ElRMN9TtMCk9Wkuf/mG/aC3okDz4dg4 iD0A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788277898; x=1788882698; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=usbV3+3pOtvfEBv9PQmV+IQ3z+lbp/nmOaEabXXhASE=; b=O0DVthkAJFTGHTgUJ4EN7hOo7aU2NxV82+S4H5mv5eS7hmERj9N+dbvz6rJCxYmoNI 7zYUTzNyXy+X4ECiq8JKHZd0and989YGjKUp4s3VJbuc9LxedTJXubTJJO8r+9mY6ZXY GYya/vhsKZDF1Ib/sqRigAzdbdu12Twd2k+O8bDfCVgyNUbPsPLWAqRd1SQUJTGJQHU4 ksiFofdVqKHT7Q/QmYG4oHzOasjZlXwjUS83gF6vLb4Whhwfx32mZR6Brwp+aDXT3rLW QwQvAWm7kZvXqLc54wdoSsLqyDe8kgxO10olG6hCAVfup6MTFVpuvAp9cF0l0DSRm28e kY9A== X-Forwarded-Encrypted: i=1; AKwUvBzR5EprTzOAnJ1lpnVy9W8xdSBWCKWnQOHjc+nK8tx3wMR5KzHCUZBEW/q88SJ/BbkDLBA4YooNCSk0tWM=@vger.kernel.org X-Gm-Message-State: AFuF++m1SrCm+Fncvu8tL/cOE9xuGBiXGnlWxFKXI1mfSkMjJ0nJ/7aj WgMns4eMrXpxXXe+6YCT6O+9M2onsUpkcNC6SiF0g2Eh5IRjVMTo6FsB X-Gm-Gg: AYBFou17dcQHR0ZXjOaLmImvI5mik4ImfiH7hZoGGOchYuDRzJMLDBtebGv4NTD6U0A ZrVqq8EjTyjS8+Nb5hbcVo4y+DoZPtEEMCNyIa7fVkla7IwM4vMgqNr6idOPXubXzOQFary9PW+ MlwBuSBQrY0+LJZ+eia9ovN9TQrlGAPe19X9nF02plk3iWb17koI8ph/ucGnYmJ3NsjJUHPPB3L w7Vqt0wcItqSsCNg3niEGECUkjvALD8th80D7LRRkIFdaYDdp8Q0c15C7kQnIU7WPEXo794sG3N cBtqOPBEmbwwGUHvrCntNEzosLXtxLb2yxYghgqSXB1CHVS/0RxMHQaKIIfJVSj+L2x3mrNJVYy fEAjWNf0TMz03v3SUpJiBgIZjfZTYwzzkJXUXgL/eM925YkXSwlYElkNNL8hD0eonwcFFVzslPr y8H8b5uOR717hdEs1KUbgNKZMyK/oDzNIdorNcUkINfuBgP7b8W7kQF0tA3ENx9bUAgNa2KsbPc PG3Zme9xEBTj+/ff1C/e6SEnIrSo3Oo1IjyoLf+ X-Received: by 2002:a05:690c:4017:b0:85d:42c3:d00b with SMTP id 00721157ae682-8686f52b910mr40076987b3.9.1788277897397; Tue, 01 Sep 2026 08:51:37 -0700 (PDT) Received: from localhost (107-220-129-194.lightspeed.chrlnc.sbcglobal.net. [107.220.129.194]) by smtp.gmail.com with ESMTPSA id 00721157ae682-85e5e181596sm78013697b3.10.2026.09.01.08.51.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 01 Sep 2026 08:51:34 -0700 (PDT) From: Matt Turner To: linux-alpha@vger.kernel.org, richard.henderson@linaro.org Cc: linmag7@gmail.com, linux-kernel@vger.kernel.org Subject: [PATCH 16/24] alpha: select HAVE_GUP_FAST Date: Tue, 1 Sep 2026 11:50:29 -0400 Message-ID: <96d45353c7c29cc3aaa3234bd960f38d2ed8889f.1788277742.git.mattst88@gmail.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The lockless GUP fast path needs the architecture to distinguish PTEs with no struct page behind them and to keep page table pages alive while a walker holds no lock. Alpha now has ARCH_HAS_PTE_SPECIAL, and it has selected MMU_GATHER_RCU_TABLE_FREE for a long time, so both requirements are met. PTEs are a single 64-bit word on Alpha, so the lockless reads that the generic walker performs cannot tear, and no arch-specific gup_fast_permitted() or ptep_get_lockless() is needed. Assisted-by: Claude:claude-opus-5 Signed-off-by: Matt Turner --- arch/alpha/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git ./arch/alpha/Kconfig ./arch/alpha/Kconfig index 87fe81bc4709..352615956b1e 100644 --- ./arch/alpha/Kconfig +++ ./arch/alpha/Kconfig @@ -26,6 +26,7 @@ config ALPHA select HAVE_ARCH_COMPILER_H select HAVE_ASM_MODVERSIONS select HAVE_DEBUG_KMEMLEAK + select HAVE_GUP_FAST select HAVE_PAGE_SIZE_8KB select HAVE_PCSPKR_PLATFORM select HAVE_PERF_EVENTS -- 2.54.0