From: Gerrit Renker

Date: Sat,  4 Oct 2008 11:13:21 +0200
> Please find below the revised patch set, addressing earlier review.
After patch 1:
  CC [M]  net/dccp/feat.o

net/dccp/feat.c:28: warning: ‘dccp_feat_clone_sp_val’ defined but not used
After patch 2:
  CC [M]  net/dccp/feat.o

net/dccp/feat.c:118: warning: ‘dccp_feat_clone_entry’ defined but not used

net/dccp/feat.c:139: warning: ‘dccp_feat_entry_destructor’ defined but not used
After patch 3:
  CC [M]  net/dccp/feat.o

net/dccp/feat.c:118: warning: ‘dccp_feat_clone_entry’ defined but not used

net/dccp/feat.c:157: warning: ‘dccp_feat_list_lookup’ defined but not used

net/dccp/feat.c:208: warning: ‘dccp_feat_push_change’ defined but not used

net/dccp/feat.c:255: warning: ‘dccp_push_empty_confirm’ defined but not used
After patch 4:
  CC [M]  net/dccp/feat.o

net/dccp/feat.c:157: warning: ‘dccp_feat_list_lookup’ defined but not used

net/dccp/feat.c:208: warning: ‘dccp_feat_push_change’ defined but not used

net/dccp/feat.c:255: warning: ‘dccp_push_empty_confirm’ defined but not used
And patch 5 makes no modifications to feat.c so things don't improve.
This can't happen.
You have to split up your patches more intelligently, such that they

are fully bisectable and at each patch point there are no new warnings

or known bugs added.