In ocfs2_search_chain, I found it has low efficiency while searching an available gd in some circumstances: 1) The lun has a great many gd(it reads lots of unavailable gd(free bits is zero)); 2) Not too many gd, but the available gd is scattered in the unavailable gd(fragmentation);
So I have an idea to optimize the search method: 1) Use the reserved member in the ocfs2_group_desc to make an available chain list(gds in the list are all available, free bits more than zero); 2) At the beginning, the chain list is the same with origin chain list; 3) While do allocation, it searches gd in the available chain list; 4) After each allocation, if some gd's free bits is zero, Remove it from the available chain list; 5) After each reclaim, if some gd's free bits change from zero to positive, Append it to the head of the available chain list; Once started with the basics outlined above, no unavailable gd will be read. Anyone has better ideas or advices? _______________________________________________ Ocfs2-devel mailing list Ocfs2-devel@oss.oracle.com https://oss.oracle.com/mailman/listinfo/ocfs2-devel
