summaryrefslogtreecommitdiff
path: root/2005/flow-accounting-ols2005/OLS2005/denijs/denijs-abstract.tex
diff options
context:
space:
mode:
Diffstat (limited to '2005/flow-accounting-ols2005/OLS2005/denijs/denijs-abstract.tex')
-rw-r--r--2005/flow-accounting-ols2005/OLS2005/denijs/denijs-abstract.tex39
1 files changed, 39 insertions, 0 deletions
diff --git a/2005/flow-accounting-ols2005/OLS2005/denijs/denijs-abstract.tex b/2005/flow-accounting-ols2005/OLS2005/denijs/denijs-abstract.tex
new file mode 100644
index 0000000..f821300
--- /dev/null
+++ b/2005/flow-accounting-ols2005/OLS2005/denijs/denijs-abstract.tex
@@ -0,0 +1,39 @@
+% [1]>linuxsymposium July 20-23rd, 2005, Ottawa, Canada
+
+% Registration Active Block I/O Scheduling System (ABISS)
+%
+% [2]Register/Submit Giel de Nijs (giel.de.nijs@philips.com)
+
+The Active Block I/O Scheduling System (ABISS) is an
+extension of the hard-disk storage subsystem of Linux.
+It is designed to provide guaranteed reading and
+writing bitrates to applications, with minimal overhead
+and low latency. The core element of ABISS is a
+scheduler that performs intelligent read-ahead or
+write-back, based on the access profile the application
+has previously requested. An adaptation of existing
+work on incorporating support for priority requests
+into the elevator (``IO scheduler'') is part of our
+implementation, and enables ABISS to ensure that
+real-time requests are served in a timely manner.
+Besides the extension to the storage subsystem, we have
+implemented experimental support for delayed allocation
+in the FAT file system, to be effectively able to
+provide the guaranteed writing bitrates. We are working
+on combining this with disk space reservations, which
+are also part of on-going development on ext3.
+Applications use the regular POSIX API, and control the
+ABISS extensions either directly through ioctls, or a
+library offering simple wrapper functions. ABISS
+contains by a user-space demon that oversees resource
+allocation and handles admission control. Also some
+minor modifications were made to file system drivers.
+ABISS currently supports FAT, VFAT, ext2, and ext3. In
+a set of experimental runs with real-life data rates on
+a deliberately not very powerful test system reflecting
+a typical embedded device, we have measured that all
+read and write operations completed within 6 ms, while
+a background load of eight concurrent greedy readers or
+writers, served in a best-effort way, experienced
+delays worse by a factor of more than 4000.
+
personal git repositories of Harald Welte. Your mileage may vary