Fujii Masao <masao.fu...@gmail.com> wrote: > Currently pg_start_backup() accesses the shared ControlFile > by using ControlFileLock with LW_EXCLUSIVE lock mode. But > since that access is read-only operation, LW_SHARED should > be chosen instead of LW_EXCLUSIVE.
Almost all operations of ControlFileLock is in LW_EXCLUSIVE, but there is one usage of LWLockConditionalAcquire(ControlFileLock, LW_SHARED) in XLogNeedsFlush(). > The attached patch changes the lock mode which pg_start_backup() > uses. Is it worth applying this patch? I think the patch is reasonable to represent what we are doing, even if there is no performance benefits from it. Regards, --- Takahiro Itagaki NTT Open Source Software Center -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
