Re: openldap.git branch mdb.master updated. 3630066843b7ca6b2cd12911d3e2fe3314cd4549

On 27/07/14 03:27, openldap-commit2devel@OpenLDAP.org wrote:

commit 3630066843b7ca6b2cd12911d3e2fe3314cd4549 Author: Howard Chu hyc@symas.com Date: Sat Jul 26 18:16:02 2014 -0700

 Fix MIPS cache coherency on Linux

 MIPS chips require manual control of on-chip caches. The cacheflush
 syscall being used here only exists on MIPS Linux, other OSs will
 require revisiting.

I may be guessing wrong what's going on here, but anyway:

CACHEFLUSH looks like it belongs before setting me_txns->mti_txnid which tells other threads/processes to use the new metapage.

If so, MDB_NOLOCK may be in trouble since it uses pick_meta() instead of mti_txnid. Should there be a separate CACHEFLUSH after writing the datapages if MDB_NOLOCK, and the current CACHEFLUSH should just flush the metapages?

Does the code contradict this comment above, or is it about something else? /* Memory ordering issues are irrelevant ... */