Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756022AbdDFVx5 (ORCPT ); Thu, 6 Apr 2017 17:53:57 -0400 Received: from mx2.suse.de ([195.135.220.15]:40260 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753077AbdDFVxt (ORCPT ); Thu, 6 Apr 2017 17:53:49 -0400 From: NeilBrown To: Matthew Wilcox Date: Fri, 07 Apr 2017 07:53:08 +1000 Cc: Jeff Layton , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-ext4@vger.kernel.org, akpm@linux-foundation.org, tytso@mit.edu, jack@suse.cz Subject: Re: [RFC PATCH 0/4] fs: introduce new writeback error tracking infrastructure and convert ext4 to use it In-Reply-To: <20170406133103.GC31725@bombadil.infradead.org> References: <87h924kh6t.fsf@notabene.neil.brown.name> <20170404115358.GH30811@bombadil.infradead.org> <1491308268.20445.4.camel@redhat.com> <20170404161247.GJ30811@bombadil.infradead.org> <1491323146.309.1.camel@redhat.com> <20170404170909.GK30811@bombadil.infradead.org> <1491421792.18658.20.camel@redhat.com> <87efx6tnbr.fsf@notabene.neil.brown.name> <20170406025530.GB31725@bombadil.infradead.org> <87inmi15md.fsf@notabene.neil.brown.name> <20170406133103.GC31725@bombadil.infradead.org> Message-ID: <871st519vf.fsf@notabene.neil.brown.name> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2062 Lines: 54 --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Thu, Apr 06 2017, Matthew Wilcox wrote: > On Thu, Apr 06, 2017 at 03:12:42PM +1000, NeilBrown wrote: >> On Wed, Apr 05 2017, Matthew Wilcox wrote: >>=20 >> > On Thu, Apr 06, 2017 at 10:02:48AM +1000, NeilBrown wrote: >> >> If you are concerned about space in 'struct address_space', just prune >> >> some wastage. >> > >> > I'm trying to (via wlists). still buggy though. >>=20 >> Cool. >> (I wonder what a wlist is.... weighted list?) > > A homonym ;-) Waitlists. Yet Another Variation of a doubly linked list. > This variation has only a single head pointer (like the hlist), allows > O(1) deletion from any point in the list (but requires that you know the > head of the list). The tail of the list is pointed to by head->prev. > > http://git.infradead.org/users/willy/linux-dax.git/shortlog/refs/heads/wl= ist > > It also needs updating to the latest tree; WW locks got revamped. So nothing points to the head, meaning you need both the node and the head to delete something. But the head is smaller. I can see how that would be useful. Thanks, NeilBrown --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEG8Yp69OQ2HB7X0l6Oeye3VZigbkFAljmuMQACgkQOeye3VZi gblV7BAAul4baewhqW/fO4B97GxfmwiPV7q5ATIUihE8INW8bRYv02zkKqoF7Zp4 3cIQHxf2Lo01nVRYKjh2CO4dOSyiPsBFW84kwrUmRxBZ5jh5T8ESpbnQ4AHGI8pJ xEcH9GfyWvHCMSPKPMzM7ZEKHxiWKvRsSKUG7KACQA4Tys+1f5ywV/YAaFl2HA3I ePTL/FtMh/9Mk0WSpdxurBXukA/LwGRMIIr/KC5U4ti1W+MvzwzvkdTLWGzEEHL0 SPDt2bxYrrdq3IqobC4n3g7hwrBpMQ3S6bJW9KlCcRQ4y2Rb/0m7X/zPTJzXDoog 88gnxso0SHeDecXhvlBzQUe9etkiw5LCaBVRFNZ+4mYU5lI2MIjDECKGxYwoznXy CC5j3/O0RdpFkKcwGN0DUYabYxeE17KeAFi23ytO/+oLXMrihatsfczuEbvWLxSg Dm1KHLsvHRcjBTEt3ZzqYCNKoenfPbEMhoxkwprrulZNLPvqT+OCXD1ezTw/X4Oz c+1Y4RLb9e3sudLZhspEFLOiW+PJAviWnUXrf2BhL38lK4mbxjKv/VAptBKx7aqf 2bF8iL2wJ0aUvF3k/f+UiHkMLbH9PYf2FYd5Sdh+Kn/PWf8RV3Y79BNKM/A/q9+E uugE4/mW/T7lOSBxe7j6ieg8MjUzdGFfeG6c9q75BOen3+HL84I= =psXi -----END PGP SIGNATURE----- --=-=-=--