When compiling EVMS 1.2.1 on 2.4 kernels with the O(1) scheduler enabled,
you will need to add this patch in addition to the normal EVMS kernel patches.

Apply with:
cd /usr/src/linux
patch -p1 < evms.h.patch

--- linux-2.4.20a/include/linux/evms/evms.h	2002/11/26 19:38:38
+++ linux-2.4.20b/include/linux/evms/evms.h	2003/02/03 18:16:49
@@ -38,6 +38,7 @@
 #define EVMS_MINOR_VERSION              2
 #define EVMS_PATCHLEVEL_VERSION         1
 
+#define O1_SCHEDULER 1
 /**
  * general defines section
  **/