README.md: Add another kernel issue found with stress-ng

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>

README.md

@@ -490,6 +490,7 @@ stress-ng has found various Kernel, QEMU bugs/regressions, and libc bugs; approp
 * [sched_ext: Don't hold scx_tasks_lock for too long](https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?b07996c7abac0fe3f70bf74b0b3f76eb7852ef5a)
 * [sched/numa: Fix the potential null pointer dereference in task_numa_work()](https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?9c70b2a33cd2aa6a5a59c5523ef053bd42265209)
 * [reiserfs panic using fsize stressor](https://bugzilla.kernel.org/show_bug.cgi?id=219497)
+* [soft-lockups: mm/page_alloc: add cond_resched in __drain_all_pages()](https://lore.kernel.org/linux-mm/3b000941-b1b6-befa-4ec9-2bff63d557c1@google.com/T/)]
 
 ## Kernel improvements that used stress-ng