From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f197.google.com (mail-pf0-f197.google.com [209.85.192.197]) by kanga.kvack.org (Postfix) with ESMTP id 5C71B440417 for ; Wed, 8 Nov 2017 10:04:49 -0500 (EST) Received: by mail-pf0-f197.google.com with SMTP id i67so2324614pfi.23 for ; Wed, 08 Nov 2017 07:04:49 -0800 (PST) Received: from bombadil.infradead.org (bombadil.infradead.org. [65.50.211.133]) by mx.google.com with ESMTPS id h13si3932092pgs.399.2017.11.08.07.04.48 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 08 Nov 2017 07:04:48 -0800 (PST) Date: Wed, 8 Nov 2017 07:04:47 -0800 From: Christoph Hellwig Subject: Re: [PATCH] vmalloc: introduce vmap_pfn for persistent memory Message-ID: <20171108150447.GA10374@infradead.org> References: <20171108095909.GA7390@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Mikulas Patocka Cc: Christoph Hellwig , Ross Zwisler , linux-mm@kvack.org, linux-nvdimm@lists.01.org, Dan Williams , dm-devel@redhat.com, Laura Abbott , Christoph Hellwig , "Kirill A . Shutemov" On Wed, Nov 08, 2017 at 07:33:09AM -0500, Mikulas Patocka wrote: > We could use the function clwb() (or arch-independent wrapper dax_flush()) > - that uses the clflushopt instruction on Broadwell or clwb on Skylake - > but it is very slow, write performance on Broadwell is only 350MB/s. > > So in practice I use the movnti instruction that bypasses cache. The > write-combining buffer is flushed with sfence. And what do you do for an architecture with virtuall indexed caches? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org