git: 9front

Download patch

ref: eb67864ff5677ab98342a6ca608c2d01e34595af
parent: 37584624cf000843d2c738c48f1c9c9931cb3cbb
author: cinap_lenrek <cinap_lenrek@gmx.de>
date: Sat Jul 27 05:25:36 EDT 2013 

ether82563: remove buffer pool optimizations

rx pool exhaustion causes the system to deadlock when netbooted.
queue management should (etheroq) already makes sure the systen
can keep up with the data thowing away buffers.


--- a/sys/src/9/pc/ether82563.c
+++ b/sys/src/9/pc/ether82563.c
@@ -416,7 +416,6 @@
 	Ntd		= 128,		/* power of two */
 	Nrb		= 512+512,	/* private receive buffers per Ctlr */
 	Rbalign		= BY2PG,	/* rx buffer alignment */
-	Npool		= 8,
 };
 
 /*
@@ -492,7 +491,6 @@
 	Ctlr	*next;
 	int	active;
 	int	type;
-	int	pool;
 	u16int	eeprom[0x40];
 
 	QLock	alock;			/* attach */
@@ -549,31 +547,11 @@
 	u32int	pba;			/* packet buffer allocation */
 };
 
-typedef struct Rbpool Rbpool;
-struct Rbpool {
-	union {
-		struct {
-			Lock;
-			Block	*b;
-			uint	nstarve;
-			uint	nwakey;
-			uint	starve;
-			Rendez;
-		};
-		uchar pad[128];		/* cacheline */
-	};
-
-	Block	*x;
-	uint	nfast;
-	uint	nslow;
-};
-
 #define csr32r(c, r)	(*((c)->nic+((r)/4)))
 #define csr32w(c, r, v)	(*((c)->nic+((r)/4)) = (v))
 
 static	Ctlr	*i82563ctlrhead;
 static	Ctlr	*i82563ctlrtail;
-static	Rbpool	rbtab[Npool];
 
 static char *statistics[Nstatistics] = {
 	"CRC Error",
@@ -664,7 +642,6 @@
 	int i, r;
 	uvlong tuvl, ruvl;
 	Ctlr *ctlr;
-	Rbpool *b;
 
 	p = s = smalloc(READSTR);
 	e = p + READSTR;
@@ -717,9 +694,6 @@
 	p = seprint(p, e, "txdctl: %.8ux\n", csr32r(ctlr, Txdctl));
 	p = seprint(p, e, "pba: %.8ux\n", ctlr->pba);
 
-	b = rbtab + ctlr->pool;
-	p = seprint(p, e, "pool: fast %ud slow %ud nstarve %ud nwakey %ud starve %ud\n",
-		b->nfast, b->nslow, b->nstarve, b->nwakey, b->starve);
 	p = seprint(p, e, "speeds: 10:%ud 100:%ud 1000:%ud ?:%ud\n",
 		ctlr->speeds[0], ctlr->speeds[1], ctlr->speeds[2], ctlr->speeds[3]);
 	p = seprint(p, e, "type: %s\n", cname(ctlr));
@@ -788,139 +762,7 @@
 	csr32w(ctlr, Mta+x*4, ctlr->mta[x]);
 }
 
-static int
-icansleep(void *v)
-{
-	Rbpool *p;
-
-	p = v;
-	return p->b != nil;
-}
-
-static Block*
-i82563rballoc(Rbpool *p)
-{
-	Block *b;
-
-	for(;;){
-		if((b = p->x) != nil){
-			p->nfast++;
-			p->x = b->next;
-			b->next = nil;
-			_xinc(&b->ref);
-			return b;
-		}
-
-		ilock(p);
-		b = p->b;
-		p->b = nil;
-		if(b == nil){
-			p->nstarve++;
-			iunlock(p);
-			return nil;
-		}
-		p->nslow++;
-		iunlock(p);
-		p->x = b;
-	}
-}
-
 static void
-rbfree(Block *b, int t)
-{
-	Rbpool *p;
-
-	p = rbtab + t;
-	b->rp = b->wp = (uchar*)ROUND((uintptr)b->base, Rbalign);
-	b->flag &= ~(Bipck | Budpck | Btcpck | Bpktck);
-
-	ilock(p);
-	b->next = p->b;
-	p->b = b;
-	if(p->starve){
-		if(0)
-			iprint("wakey %d; %d %d\n", t, p->nstarve, p->nwakey);
-		p->nwakey++;
-		p->starve = 0;
-		wakeup(p);
-	}
-	iunlock(p);
-}
-
-static void
-rbfree0(Block *b)
-{
-	rbfree(b, 0);
-}
-
-static void
-rbfree1(Block *b)
-{
-	rbfree(b, 1);
-}
-
-static void
-rbfree2(Block *b)
-{
-	rbfree(b, 2);
-}
-
-static void
-rbfree3(Block *b)
-{
-	rbfree(b, 3);
-}
-
-static void
-rbfree4(Block *b)
-{
-	rbfree(b, 4);
-}
-
-static void
-rbfree5(Block *b)
-{
-	rbfree(b, 5);
-}
-
-static void
-rbfree6(Block *b)
-{
-	rbfree(b, 6);
-}
-
-static void
-rbfree7(Block *b)
-{
-	rbfree(b, 7);
-}
-
-static Freefn freetab[Npool] = {
-	rbfree0,
-	rbfree1,
-	rbfree2,
-	rbfree3,
-	rbfree4,
-	rbfree5,
-	rbfree6,
-	rbfree7,
-};
-
-static int
-newpool(void)
-{
-	static int seq;
-
-	if(seq == nelem(freetab))
-		return -1;
-	if(freetab[seq] == nil){
-		print("82563: bad freetab\n");
-		return -1;
-	}
-	return seq++;
-}
-
-static void
 i82563im(Ctlr *ctlr, int im)
 {
 	ilock(&ctlr->imlock);
@@ -1028,38 +870,22 @@
 	}
 }
 
-static int
-i82563replenish(Ctlr *ctlr, int maysleep)
+static void
+i82563replenish(Ctlr *ctlr)
 {
 	uint rdt, i;
 	Block *bp;
-	Rbpool *p;
 	Rd *rd;
 
-	rdt = ctlr->rdt;
-	p = rbtab + ctlr->pool;
 	i = 0;
-	for(; NEXT(rdt, ctlr->nrd) != ctlr->rdh; rdt = NEXT(rdt, ctlr->nrd)){
+	for(rdt = ctlr->rdt; NEXT(rdt, ctlr->nrd) != ctlr->rdh; rdt = NEXT(rdt, ctlr->nrd)){
 		rd = &ctlr->rdba[rdt];
 		if(ctlr->rb[rdt] != nil){
 			iprint("82563: tx overrun\n");
 			break;
 		}
-	redux:
-		bp = i82563rballoc(p);
-		if(bp == nil){
-			if(rdt - ctlr->rdh >= 16)
-				break;
-			print("i82563%d: no rx buffers\n", ctlr->pool);
-			if(maysleep == 0)
-				return -1;
-			ilock(p);
-			p->starve = 1;
-			iunlock(p);
-			sleep(p, icansleep, p);
-			goto redux;
-		}
 		i++;
+		bp = allocb(ctlr->rbsz + Rbalign);
 		ctlr->rb[rdt] = bp;
 		rd->addr[0] = PCIWADDR(bp->rp);
 		rd->addr[1] = 0;
@@ -1071,7 +897,6 @@
 		ctlr->rdt = rdt;
 		csr32w(ctlr, Rdt, rdt);
 	}
-	return 0;
 }
 
 static void
@@ -1160,14 +985,14 @@
 	for(;;){
 		i82563im(ctlr, im);
 		ctlr->rsleep++;
-		i82563replenish(ctlr, 1);
+		i82563replenish(ctlr);
 		sleep(&ctlr->rrendez, i82563rim, ctlr);
 
 		rdh = ctlr->rdh;
 		for(;;){
-			rd = &ctlr->rdba[rdh];
 			rim = ctlr->rim;
 			ctlr->rim = 0;
+			rd = &ctlr->rdba[rdh];
 			if(!(rd->status & Rdd))
 				break;
 
@@ -1207,12 +1032,10 @@
 			} else
 				freeb(bp);
 			ctlr->rb[rdh] = nil;
-			rd->status = 0;
 			ctlr->rdfree--;
 			ctlr->rdh = rdh = NEXT(rdh, ctlr->nrd);
 			if(ctlr->nrd-ctlr->rdfree >= 32 || (rim & Rxdmt0))
-				if(i82563replenish(ctlr, 0) == -1)
-					break;
+				i82563replenish(ctlr);
 		}
 	}
 }
@@ -1460,8 +1283,6 @@
 i82563attach(Ether *edev)
 {
 	char name[KNAMELEN];
-	int i;
-	Block *bp;
 	Ctlr *ctlr;
 
 	ctlr = edev->ctlr;
@@ -1490,10 +1311,6 @@
 	ctlr->tdba = (Td*)(ctlr->rdba + ctlr->nrd);
 
 	if(waserror()){
-		while(bp = i82563rballoc(rbtab + ctlr->pool)){
-			bp->free = nil;
-			freeb(bp);
-		}
 		free(ctlr->tb);
 		ctlr->tb = nil;
 		free(ctlr->rb);
@@ -1504,12 +1321,6 @@
 		nexterror();
 	}
 
-	for(i = 0; i < Nrb; i++){
-		bp = allocb(ctlr->rbsz + Rbalign);
-		bp->free = freetab[ctlr->pool];
-		freeb(bp);
-	}
-
 	snprint(name, sizeof name, "#l%dl", edev->ctlrno);
 	if(csr32r(ctlr, Status) & Tbimode)
 		kproc(name, serdeslproc, edev);		/* mac based serdes */
@@ -2037,10 +1848,6 @@
 {
 	Pcidev *p;
 
-	if((ctlr->pool = newpool()) == -1){
-		print("%s: no pool\n", cname(ctlr));
-		return -1;
-	}
 	p = ctlr->pcidev;
 	ctlr->nic = vmap(ctlr->port, p->mem[0].size);
 	if(ctlr->nic == nil){
-- 
⑨