9os

commit 333e833cab42cde776b250263306fc19edb22e6f
parent f82f4e89c15cfb1b8f019d6710ba40dce50609bf
Author: Roberto E. Vargas Caballero <roberto.vargas@midokura.com>
Date:   Tue, 15 Nov 2022 21:31:19 +0100

os9: Remove free list of procs

We are running over the full array of procs almost all the times,
so for now it is better to do it always and delay such optimizations
to later.

Diffstat:
M
include/os9/os9.h
 | 
9
++-------
M
src/os9/proc.c
 | 
61
+++++++++++++++++++++++++++++++------------------------------

2 files changed, 33 insertions(+), 37 deletions(-)
diff --git a/include/os9/os9.h b/include/os9/os9.h
@@ -86,6 +86,7 @@ enum pmodes {
 	PWARM_START = 'W',
 	PIDLE = 'I',
 	PNORMAL = 'N',
+	PFREE = 'F',
 };
 
 enum tflags {
@@ -173,13 +174,9 @@ struct mpoint {
 
 /**
  * @tid: Task identifier.
- * @ptid: Parent Task identifier. -1 if it is the main task of a process.
- * @pid: Process identifier.
- * @ppid: Parent process identifier. -1 for all the task of the bootup process.
+ * @ptid: Parent Task identifier. -1 for the initial task.
  * @tname: Name of the task.
  * @tentry: Entry point for the task.
- * @pname: Name of the process.
- * @pentry: Entry point for the process (start/restart address).
  * @prio:
  * @baseprio:
  * @retainprio:
@@ -213,8 +210,6 @@ struct task {
 
 	char *tname;
 	void *tentry;
-	char *pname;
-	void *pentry;
 
 	int prio;
 	int baseprio;
diff --git a/src/os9/proc.c b/src/os9/proc.c
@@ -18,7 +18,7 @@ struct fdset {
 };
 
 static Task tasktab[NR_TASKS];
-static Task *freel;
+static mutex_t procm;
 
 static void
 initfn(void)
@@ -31,10 +31,9 @@ iproc(void)
 	Task *tp;
 
 	for (tp = tasktab; tp < &tasktab[NR_TASKS]; ++tp) {
-		tp->tid = tp->ptid = tp->pid = tp->ppid = -1;
-		tp->next  = (tp < &tasktab[NR_TASKS-1]) ? tp+1 : NULL;
+		tp->tid = tp->ptid = -1;
+		tp->mode = PFREE;
 	}
-	freel = tasktab;
 
 	if ((tp = kproc(initfn)) == NULL)
 		panic("init task failed");
@@ -80,7 +79,7 @@ getntask(int n, Task **tpp)
 	tp = &tasktab[n];
 
 	lock(&tp->m);
-	if (tp->mode == PDISABLED) {
+	if (tp->mode == PDISABLED || tp->mode == PFREE) {
 		unlock(&tp->m);
 		return 0;
 	}
@@ -92,16 +91,23 @@ getntask(int n, Task **tpp)
 Task *
 gettask(int tid)
 {
-	Task *tp;
+	Task *tp, *p;
 
-	for (tp = tasktab; tp < &tasktab[NR_TASKS]; ++tp) {
-		lock(&tp->m);
-		if (tp->mode != PDISABLED && tp->tid == tid)
-			return tp;
+	tp = NULL;
+	lock(&procm);
+	for (p = tasktab; p < &tasktab[NR_TASKS]; ++p) {
+		lock(&p->m);
+		if (p->tid == tid
+		&& p->mode != PDISABLED
+		&& p->mode != PFREE) {
+			tp = p;
+			break;
+		}
 		unlock(&tp->m);
 	}
+	unlock(&procm);
 
-	return NULL;
+	return tp;
 }
 
 int
@@ -168,20 +174,22 @@ static Task *
 newslot(void)
 {
 	Task *tp;
-	static mutex_t m;
 
-	lock(&m);
-	if (!freel) {
-		tp = NULL;
-		errno = ENOMEM;
-	} else {
-		tp = freel;
-		freel = tp->next;
+	lock(&procm);
+	for (tp = tasktab; tp < &tasktab[NR_TASKS]; tp++) {
+		lock(&tp->m);
+		if (tp->mode == PFREE) {
+			tp->mode = PDISABLED;
+			break;
+		}
+		unlock(&tp->m);
 	}
-	lock(&tp->m);
-	unlock(&m);
+	unlock(&procm);
 
-	tp->next = NULL;
+	if (tp == &tasktab[NR_TASKS]) {
+		errno = ENOMEM;
+		return NULL;
+	}
 
 	return tp;
 }
@@ -300,8 +308,6 @@ clone(Task *parent)
 		return NULL;
 
 	tp->ptid = parent->tid;
-	tp->pid = parent->pid;
-	tp->ppid = parent->ppid;
 
 	if (!initptable(tp) || !newstack(tp))
 		goto err;
@@ -336,7 +342,7 @@ rfork(int flags)
 
 	if ((flags & (RFMEM|RFPROC)) == 0
 	||  (flags & (RFNAMEG|RFCNAMEG))  == (RFNAMEG|RFCNAMEG)
-	||  (flags & (RFFDG|RFCFDG))  == (RFFDG|RFCFDG)) {
+	||  (flags & (RFFDG|RFCFDG)) == (RFFDG|RFCFDG)) {
 		errno = EINVAL;
 		return -1;
 	}
@@ -424,15 +430,10 @@ kproc(void *fn)
 	tp->ns = NULL;
 
 	tp->tid = 1;
-	tp->pid = 1;
-
 	tp->ptid = -1;
-	tp->ppid = -1;
 
 	tp->tname = "init";
 	tp->tentry = fn;
-	tp->pname = "init";
-	tp->pentry = fn;
 
 	tp->prio = 0;
 	tp->baseprio = 0;