diff options
| author | Quincey Koziol <koziol@hdfgroup.org> | 2002-06-03 19:11:43 (GMT) |
|---|---|---|
| committer | Quincey Koziol <koziol@hdfgroup.org> | 2002-06-03 19:11:43 (GMT) |
| commit | d74e0290ba1a76d455dd44dc60dbe26e09c225c6 (patch) | |
| tree | dd6ae64e653dd562c5c066617d7c80616a5770e6 /release_docs | |
| parent | 373d8b0edb12fa9fb043c6ec6a532ab1364f37f7 (diff) | |
| download | hdf5-d74e0290ba1a76d455dd44dc60dbe26e09c225c6.zip hdf5-d74e0290ba1a76d455dd44dc60dbe26e09c225c6.tar.gz hdf5-d74e0290ba1a76d455dd44dc60dbe26e09c225c6.tar.bz2 | |
[svn-r5510] Purpose:
Code cleanup/bug fix
Description:
The "metadata accumulator" cache in the library (which is designed to catch
small metadata writes/reads and bundle them together into larger I/O
buffers) was incorrectly detecting the important case of metadata pieces
being written sequentially to the file, adjoining but not overlapping.
Additionally, the metadata accumulator was not being used to cache data
read in from disk, only caching writes.
Solution:
Fix accumulator to correctly cache adjoining metadata writes and also to
cache metadata read from disk.
Between these two fixes, the number of I/O requests which resulted in actual
reads/writes to the filesystem dropped from 393 requests to 82 for the
particular test I was using. :-)
Platforms tested:
Solaris 2.7 (arabica) w/FORTRAN & FreeBSD 4.5 (sleipnir) w/C++
Diffstat (limited to 'release_docs')
| -rw-r--r-- | release_docs/RELEASE.txt | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/release_docs/RELEASE.txt b/release_docs/RELEASE.txt index 8683f86..1ec6ce2 100644 --- a/release_docs/RELEASE.txt +++ b/release_docs/RELEASE.txt @@ -166,6 +166,9 @@ Documentation New Features ============ + * Improved internal metadata caching, which can reduce the number of actual + I/O calls made by a substantial amount, improving + performance. QAK - 2002/06/03 * Added 'closing' parameter to VFL 'flush' callback function and H5FDflush. This allows the library to indicate that the file will be closed immediately following the call to 'flush' and can be used to avoid actions |