lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date:	Sat, 10 Mar 2012 23:33:21 +0200
From:	Sami Liedes <sami.liedes@....fi>
To:	linux-ext4@...r.kernel.org
Subject: [PATCH 0/5] Make filesystem shrinking faster and less CPU-intensive

This patch set speeds up at least resize2fs shrinking by causing its
CPU usage to drop by 99.5% by optimizing inode bitfield scanning.

Test case: A 100G ext4 filesystem filled to 50% with copies of
/usr/share/doc, shrinking to 75G on a slow disk (~5400 rpm) and fast
processor (Core i7):

Before:

# time resize2fs -p $FILESYSTEM 75G
[...]
real    96m26.852s
user    56m39.768s
sys     0m27.922s

After:

# time resize2fs -p $FILESYSTEM 75G
real    39m49.287s
user    0m16.601s
sys     0m26.606s

Sami Liedes (5):
      libext2fs: Move a modulo operation out of a hot loop.
      resize2fs: Use EXT2_FLAG_64BITS.
      libext2fs: Document EXT2_FLAG_64BITS in ext2fs_open2().
      libext2fs: Implement ext2fs_find_first_zero_generic_bmap().
      libext2fs: Implement fast find_first_zero() for bitarray bitmaps.

 lib/ext2fs/alloc.c        |   27 +++------------
 lib/ext2fs/bitops.h       |   16 ---------
 lib/ext2fs/blkmap64_ba.c  |   81 ---------------------------------------------
 lib/ext2fs/bmap64.h       |    5 ---
 lib/ext2fs/gen_bitmap64.c |   28 ---------------
 lib/ext2fs/openfs.c       |    1 -
 resize/main.c             |    3 --
 7 files changed, 5 insertions(+), 156 deletions(-)

Download attachment "signature.asc" of type "application/pgp-signature" (837 bytes)

Powered by blists - more mailing lists