1. A method of selective constant complexity dismissal in task scheduling of a plurality of tasks, each described by one of a plurality of task records, in a computing environment by a processor device, comprising: implementing a strictly increasing function to generate a plurality of unique creation stamps, each of the plurality of unique creation stamps increasing over time pursuant to the strictly increasing function; labeling a new task with a new unique creation stamp of the plurality of unique creation stamps; implementing a dismissal action by at least one of a list of dismissal rules against at least one of the plurality of tasks, wherein the one of the list of dismissal rules holds a minimal valid creation (MVC) stamp, the MVC stamp updated when the dismissal action for the one of the list of dismissal rules is executed; identifying a match between one of the list of dismissal rules referring to criteria unrelated to the unique creation stamps and a specific attribute of the task and determining whether the task has a unique creation stamp lower than the MVS stamp; dismissing the task to thereby prevent execution thereof, if the specific attribute of the task matches the one of the list of dismissal rules and has a unique creation stamp lower than the MVC stamp; and executing the task, if the specific attribute of the task does not match the list of dismissal rules or if the task has a unique creation stamp that is not lower than the MVC stamp.