Re: Watch Performance

On Fri, Apr 21, 2006 at 11:10:21AM -0400, Linda Knippers wrote: > > > Al, proposed a different solution. You might want to check with him for > > details. It was discussed at the Monday Telecon. > > Maybe Al could post something? With the buzz on the phone line some > of the discussion was hard to follow. Basically, add 3 families of rule lists. Rule that has one AUDIT_INODE or AUDIT_WATCH field and would currently sit in audit_filter_list[n] would be moved to audit_filter_list[AUDIT_NR_FILTERS + n * 31 + ino % 31] where ino is inode number from the AUDIT_INODE/AUDIT_WATCH field of that rule. Everything else would remain where it is now. If ->ino changes during the lifetime, rule would have to be moved between these lists. When we are trying to match context with rules on (current) list #n, we _know_ that many of them won't match just on the grounds of ->ino mismatch. With that splitting of lists we can skip most of those - rules from the current list #n will be on list #n and 31 lists starting with AUDIR_NR_FILTERS + 31*n. We only need to scan n (that's where non-watch rules remain) AUDIT_NR_FILTERS + 31*n + ctx->names[i].ino % 31 for each i less than ctx->name_count. Everything else is not going to match and doesn't have to be looked at.