proc: Remove kernel stack swapping support, part 6

- Remove most checks of the P_INMEM flag.
- Some uses remain since a few userspace tools, e.g., ps(1) and top(1)
  expect the flag to be set.  These can be cleaned up but the code has
  most likely been copy-pasted elsewhere and while linger for a long
  time.

Tested by:	pho
Reviewed by:	alc, imp, kib
Differential Revision:	https://reviews.freebsd.org/D46117

sys/ddb/db_command.c

@@ -871,10 +871,7 @@ db_stack_trace(db_expr_t tid, bool hastid, db_expr_t count, char *modif)
 	else
 		pid = -1;
 	db_printf("Tracing pid %d tid %ld td %p\n", pid, (long)td->td_tid, td);
-	if (td->td_proc != NULL && (td->td_proc->p_flag & P_INMEM) == 0)
-		db_printf("--- swapped out\n");
-	else
-		db_trace_thread(td, count);
+	db_trace_thread(td, count);
 }
 
 static void
@@ -898,10 +895,7 @@ _db_stack_trace_all(bool active_only)
 				db_printf("\nTracing command %s pid %d"
 				    " tid %ld td %p\n", td->td_proc->p_comm,
 				    td->td_proc->p_pid, (long)td->td_tid, td);
-			if (td->td_proc->p_flag & P_INMEM)
-				db_trace_thread(td, -1);
-			else
-				db_printf("--- swapped out\n");
+			db_trace_thread(td, -1);
 			if (db_pager_quit) {
 				kdb_jmpbuf(prev_jb);
 				return;

sys/ddb/db_ps.c

@@ -215,8 +215,6 @@ db_ps_proc(struct proc *p)
 	state[1] = '\0';
 
 	/* Additional process state flags. */
-	if (!(p->p_flag & P_INMEM))
-		strlcat(state, "W", sizeof(state));
 	if (p->p_flag & P_TRACED)
 		strlcat(state, "X", sizeof(state));
 	if (p->p_flag & P_WEXIT && p->p_state != PRS_ZOMBIE)

sys/ddb/db_thread.c

@@ -87,11 +87,8 @@ db_show_threads(db_expr_t addr, bool hasaddr, db_expr_t cnt, char *mod)
 		    (void *)thr->td_kstack);
 		prev_jb = kdb_jmpbuf(jb);
 		if (setjmp(jb) == 0) {
-			if (thr->td_proc->p_flag & P_INMEM) {
-				if (db_trace_thread(thr, 1) != 0)
-					db_printf("***\n");
-			} else
-				db_printf("*** swapped out\n");
+			if (db_trace_thread(thr, 1) != 0)
+				db_printf("***\n");
 		}
 		kdb_jmpbuf(prev_jb);
 		thr = kdb_thr_next(thr);

sys/fs/procfs/procfs_status.c

@@ -61,6 +61,7 @@
 int
 procfs_doprocstatus(PFS_FILL_ARGS)
 {
+	struct timeval start, ut, st;
 	struct session *sess;
 	struct thread *tdfirst;
 	struct tty *tp;
@@ -121,21 +122,16 @@ procfs_doprocstatus(PFS_FILL_ARGS)
 		wmesg = "nochan";
 	thread_unlock(tdfirst);
 
-	if (p->p_flag & P_INMEM) {
-		struct timeval start, ut, st;
-
-		PROC_STATLOCK(p);
-		calcru(p, &ut, &st);
-		PROC_STATUNLOCK(p);
-		start = p->p_stats->p_start;
-		getboottime(&boottime);
-		timevaladd(&start, &boottime);
-		sbuf_printf(sb, " %jd,%ld %jd,%ld %jd,%ld",
-		    (intmax_t)start.tv_sec, start.tv_usec,
-		    (intmax_t)ut.tv_sec, ut.tv_usec,
-		    (intmax_t)st.tv_sec, st.tv_usec);
-	} else
-		sbuf_printf(sb, " -1,-1 -1,-1 -1,-1");
+	PROC_STATLOCK(p);
+	calcru(p, &ut, &st);
+	PROC_STATUNLOCK(p);
+	start = p->p_stats->p_start;
+	getboottime(&boottime);
+	timevaladd(&start, &boottime);
+	sbuf_printf(sb, " %jd,%ld %jd,%ld %jd,%ld",
+	    (intmax_t)start.tv_sec, start.tv_usec,
+	    (intmax_t)ut.tv_sec, ut.tv_usec,
+	    (intmax_t)st.tv_sec, st.tv_usec);
 
 	sbuf_printf(sb, " %s", wmesg);
 

sys/i386/linux/linux_ptrace_machdep.c

@@ -213,7 +213,7 @@ linux_proc_read_fpxregs(struct thread *td, struct linux_pt_fpxreg *fpxregs)
 {
 
 	PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
-	if (cpu_fxsr == 0 || (td->td_proc->p_flag & P_INMEM) == 0)
+	if (cpu_fxsr == 0)
 		return (EIO);
 	bcopy(&get_pcb_user_save_td(td)->sv_xmm, fpxregs, sizeof(*fpxregs));
 	return (0);
@@ -224,7 +224,7 @@ linux_proc_write_fpxregs(struct thread *td, struct linux_pt_fpxreg *fpxregs)
 {
 
 	PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
-	if (cpu_fxsr == 0 || (td->td_proc->p_flag & P_INMEM) == 0)
+	if (cpu_fxsr == 0)
 		return (EIO);
 	bcopy(fpxregs, &get_pcb_user_save_td(td)->sv_xmm, sizeof(*fpxregs));
 	return (0);

sys/kern/kern_proc.c

@@ -1148,10 +1148,7 @@ fill_kinfo_proc_only(struct proc *p, struct kinfo_proc *kp)
 		kp->ki_ssize = vm->vm_ssize;
 	} else if (p->p_state == PRS_ZOMBIE)
 		kp->ki_stat = SZOMB;
-	if (kp->ki_flag & P_INMEM)
-		kp->ki_sflag = PS_INMEM;
-	else
-		kp->ki_sflag = 0;
+	kp->ki_sflag = PS_INMEM;
 	/* Calculate legacy swtime as seconds since 'swtick'. */
 	kp->ki_swtime = (ticks - p->p_swtick) / hz;
 	kp->ki_pid = p->p_pid;

sys/kern/kern_racct.c

@@ -332,12 +332,6 @@ racct_getpcpu(struct proc *p, u_int pcpu)
 
 	ASSERT_RACCT_ENABLED();
 
-	/*
-	 * If the process is swapped out, we count its %cpu usage as zero.
-	 * This behaviour is consistent with the userland ps(1) tool.
-	 */
-	if ((p->p_flag & P_INMEM) == 0)
-		return (0);
 	swtime = (ticks - p->p_swtick) / hz;
 
 	/*

sys/kern/sys_process.c

@@ -71,7 +71,7 @@
 #define	PROC_ASSERT_TRACEREQ(p)	MPASS(((p)->p_flag2 & P2_PTRACEREQ) != 0)
 
 /*
- * Functions implemented using PROC_ACTION():
+ * Functions implemented below:
  *
  * proc_read_regs(proc, regs)
  *	Get the current user-visible register set from the process
@@ -96,43 +96,32 @@
  *	Arrange for the process to trap after executing a single instruction.
  */
 
-#define	PROC_ACTION(action) do {					\
-	int error;							\
-									\
-	PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);			\
-	if ((td->td_proc->p_flag & P_INMEM) == 0)			\
-		error = EIO;						\
-	else								\
-		error = (action);					\
-	return (error);							\
-} while (0)
-
 int
 proc_read_regs(struct thread *td, struct reg *regs)
 {
-
-	PROC_ACTION(fill_regs(td, regs));
+	PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
+	return (fill_regs(td, regs));
 }
 
 int
 proc_write_regs(struct thread *td, struct reg *regs)
 {
-
-	PROC_ACTION(set_regs(td, regs));
+	PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
+	return (set_regs(td, regs));
 }
 
 int
 proc_read_dbregs(struct thread *td, struct dbreg *dbregs)
 {
-
-	PROC_ACTION(fill_dbregs(td, dbregs));
+	PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
+	return (fill_dbregs(td, dbregs));
 }
 
 int
 proc_write_dbregs(struct thread *td, struct dbreg *dbregs)
 {
-
-	PROC_ACTION(set_dbregs(td, dbregs));
+	PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
+	return (set_dbregs(td, dbregs));
 }
 
 /*
@@ -142,15 +131,15 @@ proc_write_dbregs(struct thread *td, struct dbreg *dbregs)
 int
 proc_read_fpregs(struct thread *td, struct fpreg *fpregs)
 {
-
-	PROC_ACTION(fill_fpregs(td, fpregs));
+	PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
+	return (fill_fpregs(td, fpregs));
 }
 
 int
 proc_write_fpregs(struct thread *td, struct fpreg *fpregs)
 {
-
-	PROC_ACTION(set_fpregs(td, fpregs));
+	PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
+	return (set_fpregs(td, fpregs));
 }
 
 static struct regset *
@@ -295,51 +284,51 @@ proc_write_regset(struct thread *td, int note, struct iovec *iov)
 int
 proc_read_regs32(struct thread *td, struct reg32 *regs32)
 {
-
-	PROC_ACTION(fill_regs32(td, regs32));
+	PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
+	return (fill_regs32(td, regs32));
 }
 
 int
 proc_write_regs32(struct thread *td, struct reg32 *regs32)
 {
-
-	PROC_ACTION(set_regs32(td, regs32));
+	PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
+	return (set_regs32(td, regs32));
 }
 
 int
 proc_read_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
 {
-
-	PROC_ACTION(fill_dbregs32(td, dbregs32));
+	PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
+	return (fill_dbregs32(td, dbregs32));
 }
 
 int
 proc_write_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
 {
-
-	PROC_ACTION(set_dbregs32(td, dbregs32));
+	PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
+	return (set_dbregs32(td, dbregs32));
 }
 
 int
 proc_read_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
 {
-
-	PROC_ACTION(fill_fpregs32(td, fpregs32));
+	PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
+	return (fill_fpregs32(td, fpregs32));
 }
 
 int
 proc_write_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
 {
-
-	PROC_ACTION(set_fpregs32(td, fpregs32));
+	PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
+	return (set_fpregs32(td, fpregs32));
 }
 #endif
 
 int
 proc_sstep(struct thread *td)
 {
-
-	PROC_ACTION(ptrace_single_step(td));
+	PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
+	return (ptrace_single_step(td));
 }
 
 int

sys/sys/proc.h

@@ -835,7 +835,7 @@ struct proc {
 #define	P_TOTAL_STOP	0x02000000	/* Stopped in stop_all_proc. */
 #define	P_INEXEC	0x04000000	/* Process is in execve(). */
 #define	P_STATCHILD	0x08000000	/* Child process stopped or exited. */
-#define	P_INMEM		0x10000000	/* Loaded into memory. */
+#define	P_INMEM		0x10000000	/* Loaded into memory, always set. */
 #define	P_UNUSED1	0x20000000	/* --available-- */
 #define	P_UNUSED2	0x40000000	/* --available-- */
 #define	P_PPTRACE	0x80000000	/* PT_TRACEME by vforked child. */

sys/sys/user.h

@@ -225,7 +225,7 @@ void fill_kinfo_proc(struct proc *, struct kinfo_proc *);
  *  Legacy PS_ flag.  This moved to p_flag but is maintained for
  *  compatibility.
  */
-#define	PS_INMEM	0x00001		/* Loaded into memory. */
+#define	PS_INMEM	0x00001		/* Loaded into memory, always true. */
 
 /* ki_sessflag values */
 #define	KI_CTTY		0x00000001	/* controlling tty vnode active */

sys/vm/vm_swapout.c

@@ -383,13 +383,6 @@ vm_daemon(void)
 			limit = OFF_TO_IDX(
 			    qmin(rsslim.rlim_cur, rsslim.rlim_max));
 
-			/*
-			 * let processes that are swapped out really be
-			 * swapped out set the limit to nothing (will force a
-			 * swap-out.)
-			 */
-			if ((p->p_flag & P_INMEM) == 0)
-				limit = 0;	/* XXX */
 			vm = vmspace_acquire_ref(p);
 			_PHOLD(p);
 			PROC_UNLOCK(p);