On Wed, Jun 01, 2016 at 03:17:14PM +0200, Gernot Hillier wrote: > I repeated the discussed tests and found comparable results on this machine: > > - 3 seconds dpkg install time on ext3 vs. 80 seconds for ext4 > on same partition for same package > - 40 ms for fallocate+write+sync_file_range for writing a few bytes > - 15 ms for write+fdatasync vs. 45 ms for BLKZEROOUT on raw device > > So this seems to be not bound to one specific disk+controller setup, but > it still can't be a common problem affecting many people as then we > would see more reports about it... OK, so let's try to get common baseline, shall we? I'm using as my test package: http://debug.mirrors.debian.org/debian-debug/pool/main/e/e2fsprogs/e2fsprogs-dbgsym_1.43-2_amd64.deb % ls -s /tmp/e2fsprogs-dbgsym_1.43-3_amd64.deb 1108 /tmp/e2fsprogs-dbgsym_1.43-3_amd64.deb % md5sum /tmp/e2fsprogs-dbgsym_1.43-3_amd64.deb 148ee631f46ed2e05a17faf36cc9d630 /tmp/e2fsprogs-dbgsym_1.43-3_amd64.deb # dpkg --purge e2fsprogs-dbgsym (Reading database ... 322967 files and directories currently installed.) Removing e2fsprogs-dbgsym (1.43-3) ... # /usr/bin/time dpkg --force-depends -i /tmp/e2fsprogs-dbgsym_1.43-3_amd64.deb Selecting previously unselected package e2fsprogs-dbgsym. (Reading database ... 322947 files and directories currently installed.) Preparing to unpack .../e2fsprogs-dbgsym_1.43-3_amd64.deb ... Unpacking e2fsprogs-dbgsym (1.43-3) ... Setting up e2fsprogs-dbgsym (1.43-3) ... 0.21user 0.19system 0:00.54elapsed 74%CPU (0avgtext+0avgdata 73188maxresident)k 0inputs+10168outputs (0major+24935minor)pagefaults 0swaps Something else would be useful is to make sure /tmp is a tmpfs mounted file system (so you don't get any I/O's caused by /tmp), and then do: # dpkg --purge e2fsprogs-dbgsym # btrace /dev/sda3 > /tmp/btrace.out & # /usr/bin/time dpkg --force-depends -i /tmp/e2fsprogs-dbgsym_1.43-3_amd64.deb # kill %btrace Replace /dev/sda3 with the device name of your root partition, and then send us the compressed btrace.out file, which might give us a clue about what is going on. Cheers, - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
