Description of problem: GFS2 uses too much memory. For every buffer, gfs2 has a special lock structure called a glock, due to the type of page-level locking it does. Right now, GFS2 allocates an inode structure to keep track of the address space associated with metadata. We need to reduce the memory requirements. We can do this by making it only allocate the address space inode when it's needed, on the fly. That reduces the size of each glock considerably. Version-Release number of selected component (if applicable): RHEL5.2 How reproducible: Always Steps to Reproduce: 1. Run any program that does a lot of writing Actual results: Lots of memory allocated per page. Expected results: Less memory allocated. Additional info: There is an upstream patch to do this that needs to be crosswritten for RHEL5.
Created attachment 291295 [details] Patch to fix the problem Here is the patch I'll be posting to rhkernel-list.
Patch compiled and tested on "kool", and posted to rhkernel-list. Setting status to modified and rerouting to Don Zickus.
in 2.6.18-71.el5 You can download this test kernel from http://people.redhat.com/dzickus/el5
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on the solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHBA-2008-0314.html