From mboxrd@z Thu Jan 1 00:00:00 1970 From: Simon Kagstrom Subject: Squashfs performance (3.3 vs 4.0 in mainline) Date: Thu, 10 Dec 2009 15:02:43 +0100 Message-ID: <20091210150243.2ed788f4@marrow.netinsight.se> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: Sender: linux-embedded-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: linux-embedded Cc: Phillip Lougher Hi! I'm running 2.6.31 on a slow ARM platform and using squashfs 4.0 as shipped with the kernel. It's a Sharp LH79524, so the architecture itself isn't mainlined yet. Squashfs works well, but I've noted a performance regression compared to the out-of-tree squashfs 3.3 which we ran on 2.6.23. The new kernel is faster until the squashfs root filesystem is mounted, but after that it goes downhill. Especially mounting takes a lot more time with the new: 2.6.23 / 3.3: [ 0.01]: [ 1.250000] RAMDISK: squashfs filesystem found at block 0 [ 0.01]: [ 1.260000] RAMDISK: Loading 2156KiB [1 disk] into ram disk... done. [ 1.39]: [ 2.650000] VFS: Mounted root (squashfs filesystem) readonly. [ 0.01]: [ 2.660000] Freeing init memory: 80K 2.6.31 / 4.0: [ 0.00]: [ 1.080000] RAMDISK: squashfs filesystem found at block 0 [ 0.01]: [ 1.090000] RAMDISK: Loading 2372KiB [1 disk] into ram disk... done. [ 2.79]: [ 3.880000] VFS: Mounted root (squashfs filesystem) readonly on device 1:0. [ 0.01]: [ 3.890000] Freeing init memory: 80K (The first column is the time difference compared to last timestamp). Are there any general changes which could have caused this difference? I've tried with various mksquashfs options, and -noI makes it somewhat faster (and larger), but not near the old version. // Simon