mirror of
https://github.com/samba-team/samba.git
synced 2025-01-27 14:04:05 +03:00
11ab43084b
We saw tdb_lockall() take 71 seconds under heavy load; this is because Linux (at least) doesn't prevent new small locks being obtained while we're waiting for a big log. The workaround is to do divide and conquer using non-blocking chainlocks: if we get down to a single chain we block. Using a simple test program where children did "hold lock for 100ms, sleep for 1 second" the time to do tdb_lockall() dropped signifiantly. There are ln(hashsize) locks taken in the contended case, but that's slow anyway. More analysis is given in my blog at http://rusty.ozlabs.org/?p=120 This may also help transactions, though in that case it's the initial read lock which uses this gradual locking routine; the update-to-write-lock code is separate and still tries to update in one go. Even though ABI doesn't change, minor version bumped so behavior change can be easily detected. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
compression - Various compression algorithms (MSZIP, lzxpress) dnspython - Python module for working with DNS. nss_wrapper - Wrapper for the user and group NSS API allowing the use of other data sources. popt - Command-line option parsing library replace - Provides replacements for standard (POSIX, C99) functions not provided by the host platform. socket_wrapper - Wrapper library allowing TCP/IP traffic to be redirected over Unix domain sockets. subunit - Utilities and bindings for working with the Subunit test result reporting protocol. talloc - Hierarchical pool based memory allocator tdb - Simple but fast key/value database library, supporting multiple writers torture - Simple unit testing helper library