A method for performing garbage collection on an object heap is described. In one embodiment, such a method includes performing a copy phase on an object heap by copying live objects from a source space to a destination space. An abort condition is generated when copying an object from the source space to the destination space fails due to insufficient space. In response to the abort condition, tracing work and reference updating associated with the copy phase are terminated. A mark phase is then initiated that marks live objects in the source space. This mark phase resumes tracing work and reference updating terminated by the copy phase in order to avoid or minimize the repetition of work performed by the copy phase. A corresponding computer program product and system are also described.