diff --git a/src/afs/afs.h b/src/afs/afs.h
index 8684f22157..39a8e57d22 100644
--- a/src/afs/afs.h
+++ b/src/afs/afs.h
@@ -1392,9 +1392,14 @@ extern struct brequest afs_brs[NBRS];	/* request structures */
     (((rw) == UIO_WRITE) ? afs_write(avc, uio, io, cred, 1) : afs_read(avc, uio, cred, 1))
 
 /* Cache size truncation uses the following low and high water marks:
- * If the cache is more than 95% full (CM_DCACHECOUNTFREEPCT), the cache
- * truncation daemon is awakened and will free up space until the cache is 85%
- * (CM_DCACHESPACEFREEPCT - CM_DCACHEEXTRAPCT) full.
+ * If the cache is more than 90% full by space (CM_DCACHESPACEFREEPCT) or
+ * 95% full by # of chunks (CM_DCACHECOUNTFREEPCT), the cache truncation
+ * daemon is awakened and will start freeing space. The cache truncation
+ * daemon will continue to free space until the cache is at most 85% full
+ * by space (CM_DCACHESPACEFREEPCT - CM_DCACHEEXTRAPCT). The cache truncation
+ * daemon will also try to free space until the cache is at most 90% full by
+ * chunks (CM_DCACHECOUNTFREEPCT - CM_DCACHEEXTRAPCT), but the 85% space limit
+ * is the only limit that we must hit.
  * afs_UFSWrite and afs_GetDCache (when it needs to fetch data) will wait on
  * afs_WaitForCacheDrain if the cache is 98% (CM_WAITFORDRAINPCT) full.
  * afs_GetDownD wakes those processes once the cache is 95% full
diff --git a/src/afs/afs_dcache.c b/src/afs/afs_dcache.c
index d3c329f53e..872757ae80 100644
--- a/src/afs/afs_dcache.c
+++ b/src/afs/afs_dcache.c
@@ -397,7 +397,8 @@ u_int afs_min_cache = 0;
 
 /*!
  * If there are waiters for the cache to drain, wake them if
- * the number of free cache blocks reaches the CM_CACHESIZEDDRAINEDPCT.
+ * the number of free or discarded cache blocks reaches the
+ * CM_CACHESIZEDDRAINEDPCT limit.
  *
  * \note Environment:
  *	This routine must be called with the afs_xdcache lock held