From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f70.google.com (mail-pg0-f70.google.com [74.125.83.70]) by kanga.kvack.org (Postfix) with ESMTP id 4E4506B0033 for ; Fri, 15 Dec 2017 13:43:41 -0500 (EST) Received: by mail-pg0-f70.google.com with SMTP id a13so7579177pgt.0 for ; Fri, 15 Dec 2017 10:43:41 -0800 (PST) Received: from bombadil.infradead.org (bombadil.infradead.org. [65.50.211.133]) by mx.google.com with ESMTPS id j8si5443419pli.353.2017.12.15.10.43.38 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 15 Dec 2017 10:43:40 -0800 (PST) Date: Fri, 15 Dec 2017 10:42:56 -0800 From: Matthew Wilcox Subject: Re: [PATCH v19 3/7] xbitmap: add more operations Message-ID: <20171215184256.GA27160@bombadil.infradead.org> References: <1513079759-14169-1-git-send-email-wei.w.wang@intel.com> <1513079759-14169-4-git-send-email-wei.w.wang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1513079759-14169-4-git-send-email-wei.w.wang@intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Wei Wang Cc: virtio-dev@lists.oasis-open.org, linux-kernel@vger.kernel.org, qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org, linux-mm@kvack.org, mst@redhat.com, mhocko@kernel.org, akpm@linux-foundation.org, mawilcox@microsoft.com, david@redhat.com, penguin-kernel@I-love.SAKURA.ne.jp, cornelia.huck@de.ibm.com, mgorman@techsingularity.net, aarcange@redhat.com, amit.shah@redhat.com, pbonzini@redhat.com, liliang.opensource@gmail.com, yang.zhang.wz@gmail.com, quan.xu@aliyun.com, nilal@redhat.com, riel@redhat.com On Tue, Dec 12, 2017 at 07:55:55PM +0800, Wei Wang wrote: > +int xb_preload_and_set_bit(struct xb *xb, unsigned long bit, gfp_t gfp); I'm struggling to understand when one would use this. The xb_ API requires you to handle your own locking. But specifying GFP flags here implies you can sleep. So ... um ... there's no locking? > +void xb_clear_bit_range(struct xb *xb, unsigned long start, unsigned long end); That's xb_zero() which you deleted with the previous patch ... remember, keep things as close as possible to the bitmap API. -- 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