svn commit: r367961 - in head/sys: kern sys

[Mateusz Guzik]

Author: mjg
Date: Mon Nov 23 18:26:47 2020
New Revision: 367961
URL: https://svnweb.freebsd.org/changeset/base/367961

Log:
  thread: stash domain id to work around vtophys problems on ppc64
  
  Adding to zombie list can be perfomed by idle threads, which on ppc64 leads to
  panics as it requires a sleepable lock.
  
  Reported by:	alfredo
  Reviewed by:	kib, markj
  Fixes:	r367842 ("thread: numa-aware zombie reaping")
  Differential Revision:	https://reviews.freebsd.org/D27288

Modified:
  head/sys/kern/kern_thread.c
  head/sys/sys/proc.h

Modified: head/sys/kern/kern_thread.c
==============================================================================
--- head/sys/kern/kern_thread.c	Mon Nov 23 18:18:16 2020	(r367960)
+++ head/sys/kern/kern_thread.c	Mon Nov 23 18:26:47 2020	(r367961)
@@ -346,6 +346,7 @@ thread_ctor(void *mem, int size, void *arg, int flags)
 	td = (struct thread *)mem;
 	td->td_state = TDS_INACTIVE;
 	td->td_lastcpu = td->td_oncpu = NOCPU;
+	td->td_allocdomain = vm_phys_domain(vtophys(td));
 
 	/*
 	 * Note that td_critnest begins life as 1 because the thread is not
@@ -544,7 +545,7 @@ thread_zombie(struct thread *td)
 	struct thread_domain_data *tdd;
 	struct thread *ztd;
 
-	tdd = &thread_domain_data[vm_phys_domain(vtophys(td))];
+	tdd = &thread_domain_data[td->td_allocdomain];
 	ztd = atomic_load_ptr(&tdd->tdd_zombies);
 	for (;;) {
 		td->td_zombie = ztd;

Modified: head/sys/sys/proc.h
==============================================================================
--- head/sys/sys/proc.h	Mon Nov 23 18:18:16 2020	(r367960)
+++ head/sys/sys/proc.h	Mon Nov 23 18:26:47 2020	(r367961)
@@ -246,6 +246,7 @@ struct thread {
 	sigqueue_t	td_sigqueue;	/* (c) Sigs arrived, not delivered. */
 #define	td_siglist	td_sigqueue.sq_signals
 	u_char		td_lend_user_pri; /* (t) Lend user pri. */
+	u_char		td_allocdomain;	/* (b) NUMA domain backing this struct thread. */
 
 /* Cleared during fork1() */
 #define	td_startzero td_flags