From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?utf-8?B?SsO2cm4=?= Engel Subject: Re: [PATCH 0/3 v3] dcache: make it more scalable on large system Date: Wed, 29 May 2013 17:19:17 -0400 Message-ID: <20130529211917.GB6658@logfs.org> References: <1369273048-60256-1-git-send-email-Waiman.Long@hp.com> <20130523094201.GA24543@dastard> <519E8B5F.3080905@hp.com> <20130527020903.GR29466@dastard> <51A624E2.3000301@hp.com> <20130529184640.GA3243@fieldses.org> <20130529203700.GM6123@two.firstfloor.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: "J. Bruce Fields" , Waiman Long , Dave Chinner , Alexander Viro , Jeff Layton , Miklos Szeredi , Ian Kent , Sage Weil , Steve French , Trond Myklebust , Eric Paris , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, autofs@vger.kernel.org, ceph-devel@vger.kernel.org, linux-cifs@vger.kernel.org, linux-nfs@vger.kernel.org, "Chandramouleeswaran, Aswin" , "Norton, Scott J" To: Andi Kleen Return-path: Content-Disposition: inline In-Reply-To: <20130529203700.GM6123@two.firstfloor.org> Sender: autofs-owner@vger.kernel.org List-Id: linux-cifs.vger.kernel.org On Wed, 29 May 2013 22:37:00 +0200, Andi Kleen wrote: >=20 > > As Dave said before, is the last path component sufficient? Or how > > about an inode number? >=20 > Neither works, the profiler needs to find the file and read it. Ignoring all the complexity this would cause downstream, you could do the path lookup just once, attach some cookie to it and return the cookie ever-after. Maybe some combination of i_sb and i_ino would be good enough as a cookie. J=C3=B6rn -- Data dominates. If you've chosen the right data structures and organize= d things well, the algorithms will almost always be self-evident. Data structures, not algorithms, are central to programming. -- Rob Pike From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?utf-8?B?SsO2cm4=?= Engel Subject: Re: [PATCH 0/3 v3] dcache: make it more scalable on large system Date: Wed, 29 May 2013 17:19:17 -0400 Message-ID: <20130529211917.GB6658@logfs.org> References: <1369273048-60256-1-git-send-email-Waiman.Long@hp.com> <20130523094201.GA24543@dastard> <519E8B5F.3080905@hp.com> <20130527020903.GR29466@dastard> <51A624E2.3000301@hp.com> <20130529184640.GA3243@fieldses.org> <20130529203700.GM6123@two.firstfloor.org> Mime-Version: 1.0 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <20130529203700.GM6123@two.firstfloor.org> Sender: autofs-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="iso-8859-1" To: Andi Kleen Cc: "J. Bruce Fields" , Waiman Long , Dave Chinner , Alexander Viro , Jeff Layton , Miklos Szeredi , Ian Kent , Sage Weil , Steve French , Trond Myklebust , Eric Paris , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, autofs@vger.kernel.org, ceph-devel@vger.kernel.org, linux-cifs@vger.kernel.org, linux-nfs@vger.kernel.org, "Chandramouleeswaran, Aswin" , "Norton, Scott J" On Wed, 29 May 2013 22:37:00 +0200, Andi Kleen wrote: >=20 > > As Dave said before, is the last path component sufficient? Or how > > about an inode number? >=20 > Neither works, the profiler needs to find the file and read it. Ignoring all the complexity this would cause downstream, you could do the path lookup just once, attach some cookie to it and return the cookie ever-after. Maybe some combination of i_sb and i_ino would be good enough as a cookie. J=C3=B6rn -- Data dominates. If you've chosen the right data structures and organize= d things well, the algorithms will almost always be self-evident. Data structures, not algorithms, are central to programming. -- Rob Pike