On Mon, May 18, 2026 at 07:25:54PM +0800, Barry Song wrote: > We have clearly observed that the `fork()` operations of many > popular Android apps, such as iQiyi, Baidu Tieba, and 10086, > end up waiting on page-fault (PF) I/O when the VMA lock is > held during I/O operations. This has already become a > practical issue. I also believe this can lead to chained > waiting, since the global `mmap_lock` blocks all threads that > need to acquire it.
It's always been a terrible idea to call fork() from a multithreaded application. For example, this question: https://stackoverflow.com/questions/53601200/calling-fork-on-a-multithreaded-process or this lwn thread: https://lwn.net/Articles/674660/ Do we have any insight into why these applications are doing this horrible thing?
