From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailo.com (msg-2.mailo.com [213.182.54.12]) (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 1D1E82772C for ; Fri, 6 Oct 2023 18:46:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=mailo.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mailo.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=mailo.com header.i=@mailo.com header.b="F1xvBXAV" DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=mailo.com; s=mailo; t=1696617986; bh=RYszOFam6KVl1ypA3hz/Gcl2MPX05Hk70/Nt/veHpOM=; h=X-EA-Auth:Date:From:To:Cc:Subject:Message-ID:MIME-Version: Content-Type; b=F1xvBXAVWvtXxgW1QQNTe41Wrl1V8lgkOuvedF2t9O0VLnM/P4+c/KixHwe0EMhNF iVsVYf9i9rpf288wnN0fDJ++tNtL5+KqkRvkONOwM5R0Xpkry+Wuq0N0tan+ZP3yWB EAMt6nYiQZHghB6vvGwhbpkJyXeF/SiqIfLMS4Iw= Received: by b221-1.in.mailobj.net [192.168.90.21] with ESMTP via ip-20.mailobj.net [213.182.54.20] Fri, 6 Oct 2023 20:46:26 +0200 (CEST) X-EA-Auth: wLkTObUMxPeiTYFDpw6KkYlMjjTpxPawCOc5bmQzZOsGoLzdy2ksD4xiQuNg42zWt+KIKqlCXA9oIB3RokB0KAtS6XdsuVA+ Date: Sat, 7 Oct 2023 00:16:18 +0530 From: Deepak R Varma To: Huacai Chen , WANG Xuerui , loongarch@lists.linux.dev, linux-kernel@vger.kernel.org Cc: Ira Weiny , "Fabio M. De Francesco" Subject: kmap() transformation: Question about copy_user_highpage Message-ID: Precedence: bulk X-Mailing-List: loongarch@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Hello, I am attempting to work on replacing the kmap[_atomic]() calls by kmap_local_page() function call. A detail on this change can be found here [0]. I would like to know if this function: arch/loongarch/mm/init.c::copy_user_highpage() is currently in use or is it a dead code? If this code is not in use, can this be removed instead? However, if it is in use, can you comment why kmap_atomic() was preferred over kmap() function call? [0] https://lore.kernel.org/all/20201029222652.302358281@linutronix.de/ Thank you, Deepak.