Re: Connections hang indefinitely while taking a gin index's LWLock buffer_content lock

[Andrey Borodin]

Hi everyone! I didn't noticed this thread for too long somehow, sorry. 8 нояб. 2018 г., в 6:46, Peter Geoghegan <p...@bowt.ie> написал(а): I don't think the general "there can't be any inserters at this subtree" thing works given that we have to couple buffer locks when moving right for other reasons. We call ginStepRight() within ginFinishSplit(), for reasons that date back to bug fix commit ac4ab97e from 2013 -- that detail is probably important, because it seems to be what breaks the subtree design (we don't delete in two phases or anything in GIN). ginVacuumPostingTreeLeaves() holds LockBufferForCleanup() on subtree root b. Thus there may be no GinBtreeStack's holding pin on b at the moment. When you ginStepRight(b) to the parent in ginFinishSplit(), you always get to the buffer from your stack. Hence you can never have ginFinishSplit() deadlock with cleanup of subtree whose root is LockBufferForCleanup()'d. Is this correct or did I miss something? But we have a deadlock at hand, I'll think more about it. Something with locking protocol is clearly wrong. 11 нояб. 2018 г., в 22:33, chenhj <chjis...@163.com> написал(а): The order of get lwlock in ginRedoDeletePage() may should be change from "dbuffer->pbuffer->lbuffer" to "lbuffer->dbuffer->pbuffer" . Is this right? This looks correct to me. Best regards, Andrey Borodin.