From: Theodore Tso Subject: Re: Use of kmalloc vs vmalloc in ext4? Date: Sat, 25 Apr 2009 22:12:20 -0400 Message-ID: <20090426021220.GB10248@mit.edu> References: <6601abe90903110732n5c9df9b9td317be316921b7a6@mail.gmail.com> <532480950904052345m48bc5df5wcdc4c5e32778130c@mail.gmail.com> <20090425030703.GD13608@mit.edu> <20090425033955.GF13608@mit.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Curt Wohlgemuth , linux-ext4@vger.kernel.org To: Michael Rubin Return-path: Received: from THUNK.ORG ([69.25.196.29]:51798 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755695AbZDZCM1 (ORCPT ); Sat, 25 Apr 2009 22:12:27 -0400 Content-Disposition: inline In-Reply-To: <20090425033955.GF13608@mit.edu> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Fri, Apr 24, 2009 at 11:39:55PM -0400, Theodore Tso wrote: > P.S. What sort of flex_bg size are you using? > > EXT4-fs: not enough memory for 8198 flex groups > EXT4-fs: unable to initialize flex_bg meta info! > > Modern e2fsprogs default to using 16 block groups per flex_bg, which > means 8198 flex groups is a little over 16 TB --- which the mainline > e2fsprogs doesn't support yet. You wouldn't be using a smaller > flex_bg size for some reason, are you? Oh, never mind. I didn't realize this last night, but we allocate sbi->s_flex_counts so it is big enough in case the filesystem gets resized to the maximum size. So that's why it was trying to allocate that many flex groups. On the other hand, it means that it's much more likely for us to need the extra memory. - Ted