Return-Path: linux-nfs-owner@vger.kernel.org Received: from bombadil.infradead.org ([198.137.202.9]:59914 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752567Ab3JLImm (ORCPT ); Sat, 12 Oct 2013 04:42:42 -0400 Date: Sat, 12 Oct 2013 01:42:35 -0700 From: Christoph Hellwig To: "J. Bruce Fields" Cc: Al Viro , "J. Bruce Fields" , linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, Christoph Hellwig Subject: Re: [PATCH 4/4] dcache: don't clear DCACHE_DISCONNECTED too early Message-ID: <20131012084235.GB5649@infradead.org> References: <1378579561-26868-1-git-send-email-bfields@redhat.com> <1378579561-26868-5-git-send-email-bfields@redhat.com> <20130909004647.GK13318@ZenIV.linux.org.uk> <20130909204655.GA10599@fieldses.org> <20131011160237.GA21258@fieldses.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20131011160237.GA21258@fieldses.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Fri, Oct 11, 2013 at 12:02:37PM -0400, J. Bruce Fields wrote: > But just for fun--I did some cleanup and fixed some other quadratic > behavior here and can notice a difference on lookups of very deep > subdirectories. > > For example I'm seeing an uncached lookup of an 8000-deep directory > taking about 6 seconds, and can get that down to a tenth of a second. > > I'm not sure yet if the difference on less extreme examples is really > significant, I need to experiment some more. > > I'll do some more review and post patches and results. This sounds like and awesome improvement. How much code do you have to add for it?