Radek, On 06/20/2011 03:27 PM, Radosław Smogura wrote: > When playing with mmap I done some approach how to deal with growing > files, so...
Your approach seems to require a SysV alloc (for nattach) as well as POSIX shmem and/or mmap. Adding requirements for these syscalls certainly needs to give a good benefit for Postgres, as they presumably pose portability issues. > 3. a. Lock header when adding chunks (1st chunk is header) (we don't > want concurrent chunk allocation) Sure we don't? There are at least a dozen memory allocators for multi-threaded applications, all trying to optimize for concurrency. The programmer of a multi-threaded application doesn't need to care much about concurrent allocations. He can allocate (and free) quite a lot of tiny chunks concurrently from shared memory. Regards Markus Wanner -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers