sched/fair: sanitize vruntime of entity being placed
stable inclusion from stable-v5.10.177 commit dfdcda25fb5e3c09394a28173f24b22e7c7e4731 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I88YNP Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=dfdcda25fb5e3c09394a28173f24b22e7c7e4731 -------------------------------- commit 829c1651 upstream. When a scheduling entity is placed onto cfs_rq, its vruntime is pulled to the base level (around cfs_rq->min_vruntime), so that the entity doesn't gain extra boost when placed backwards. However, if the entity being placed wasn't executed for a long time, its vruntime may get too far behind (e.g. while cfs_rq was executing a low-weight hog), which can inverse the vruntime comparison due to s64 overflow. This results in the entity being placed with its original vruntime way forwards, so that it will effectively never get to the cpu. To prevent that, ignore the vruntime of the entity being placed if it didn't execute for much longer than the characteristic sheduler time scale. [rkagan: formatted, adjusted commit log, comments, cutoff value] Signed-off-by:Zhang Qiao <zhangqiao22@huawei.com> Co-developed-by:
Roman Kagan <rkagan@amazon.de> Signed-off-by:
Roman Kagan <rkagan@amazon.de> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20230130122216.3555094-1-rkagan@amazon.de Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by:
sanglipeng <sanglipeng1@jd.com>
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