From: Ed L. Cashin Date: Wed, 20 Sep 2006 18:36:49 +0000 (-0400) Subject: aoe: zero copy write 2 of 2 X-Git-Tag: v2.6.19-rc3~124^2~6 X-Git-Url: https://git.kernelconcepts.de/?a=commitdiff_plain;h=4f51dc5e9ae195d2e8c22e5f574e004c2f6518a4;p=karo-tx-linux.git aoe: zero copy write 2 of 2 Avoid memory copy on writes. (This patch follows patch 4.) Signed-off-by: "Ed L. Cashin" Acked-by: Alan Cox Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/block/aoe/aoe.h b/drivers/block/aoe/aoe.h index 7b1121748633..b41fdfe0f4b8 100644 --- a/drivers/block/aoe/aoe.h +++ b/drivers/block/aoe/aoe.h @@ -84,6 +84,7 @@ enum { DEVFL_PAUSE = (1<<5), DEVFL_NEWSIZE = (1<<6), /* need to update dev size in block layer */ DEVFL_MAXBCNT = (1<<7), /* d->maxbcnt is not changeable */ + DEVFL_KICKME = (1<<8), BUFFL_FAIL = 1, }; diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c index c0bdc1fe21f0..9ebc98ade3c5 100644 --- a/drivers/block/aoe/aoecmd.c +++ b/drivers/block/aoe/aoecmd.c @@ -120,7 +120,7 @@ aoecmd_ata_rw(struct aoedev *d, struct frame *f) h = (struct aoe_hdr *) skb->mac.raw; ah = (struct aoe_atahdr *) (h+1); skb->len = sizeof *h + sizeof *ah; - memset(h, 0, skb->len); + memset(h, 0, ETH_ZLEN); f->tag = aoehdr_atainit(d, h); f->waited = 0; f->buf = buf; @@ -143,8 +143,9 @@ aoecmd_ata_rw(struct aoedev *d, struct frame *f) skb_fill_page_desc(skb, 0, virt_to_page(f->bufaddr), offset_in_page(f->bufaddr), bcnt); ah->aflags |= AOEAFL_WRITE; + skb->len += bcnt; + skb->data_len = bcnt; } else { - skb_shinfo(skb)->nr_frags = 0; skb->len = ETH_ZLEN; writebit = 0; } @@ -167,8 +168,9 @@ aoecmd_ata_rw(struct aoedev *d, struct frame *f) } skb->dev = d->ifp; - skb_get(skb); - skb->next = NULL; + skb = skb_clone(skb, GFP_ATOMIC); + if (skb == NULL) + return; if (d->sendq_hd) d->sendq_tl->next = skb; else @@ -224,6 +226,29 @@ aoecmd_cfg_pkts(ushort aoemajor, unsigned char aoeminor, struct sk_buff **tail) return sl; } +static struct frame * +freeframe(struct aoedev *d) +{ + struct frame *f, *e; + int n = 0; + + f = d->frames; + e = f + d->nframes; + for (; ftag != FREETAG) + continue; + if (atomic_read(&skb_shinfo(f->skb)->dataref) == 1) { + skb_shinfo(f->skb)->nr_frags = f->skb->data_len = 0; + return f; + } + n++; + } + if (n == d->nframes) /* wait for network layer */ + d->flags |= DEVFL_KICKME; + + return NULL; +} + /* enters with d->lock held */ void aoecmd_work(struct aoedev *d) @@ -239,7 +264,7 @@ aoecmd_work(struct aoedev *d) } loop: - f = getframe(d, FREETAG); + f = freeframe(d); if (f == NULL) return; if (d->inprocess == NULL) { @@ -282,20 +307,25 @@ rexmit(struct aoedev *d, struct frame *f) n = DEFAULTBCNT / 512; if (ah->scnt > n) { ah->scnt = n; - if (ah->aflags & AOEAFL_WRITE) + if (ah->aflags & AOEAFL_WRITE) { skb_fill_page_desc(skb, 0, virt_to_page(f->bufaddr), offset_in_page(f->bufaddr), DEFAULTBCNT); + skb->len = sizeof *h + sizeof *ah + DEFAULTBCNT; + skb->data_len = DEFAULTBCNT; + } if (++d->lostjumbo > (d->nframes << 1)) if (d->maxbcnt != DEFAULTBCNT) { - iprintk("too many lost jumbo - using 1KB frames.\n"); + iprintk("e%ld.%ld: too many lost jumbo on %s - using 1KB frames.\n", + d->aoemajor, d->aoeminor, d->ifp->name); d->maxbcnt = DEFAULTBCNT; d->flags |= DEVFL_MAXBCNT; } } skb->dev = d->ifp; - skb_get(skb); - skb->next = NULL; + skb = skb_clone(skb, GFP_ATOMIC); + if (skb == NULL) + return; if (d->sendq_hd) d->sendq_tl->next = skb; else @@ -350,6 +380,10 @@ rexmit_timer(ulong vp) rexmit(d, f); } } + if (d->flags & DEVFL_KICKME) { + d->flags &= ~DEVFL_KICKME; + aoecmd_work(d); + } sl = d->sendq_hd; d->sendq_hd = d->sendq_tl = NULL; @@ -552,23 +586,27 @@ aoecmd_ata_rsp(struct sk_buff *skb) case WIN_WRITE: case WIN_WRITE_EXT: if (f->bcnt -= n) { + skb = f->skb; f->bufaddr += n; put_lba(ahout, f->lba += ahout->scnt); n = f->bcnt; if (n > DEFAULTBCNT) n = DEFAULTBCNT; ahout->scnt = n >> 9; - if (ahout->aflags & AOEAFL_WRITE) - skb_fill_page_desc(f->skb, 0, + if (ahout->aflags & AOEAFL_WRITE) { + skb_fill_page_desc(skb, 0, virt_to_page(f->bufaddr), offset_in_page(f->bufaddr), n); + skb->len = sizeof *hout + sizeof *ahout + n; + skb->data_len = n; + } f->tag = newtag(d); hout->tag = cpu_to_be32(f->tag); skb->dev = d->ifp; - skb_get(f->skb); - f->skb->next = NULL; + skb = skb_clone(skb, GFP_ATOMIC); spin_unlock_irqrestore(&d->lock, flags); - aoenet_xmit(f->skb); + if (skb) + aoenet_xmit(skb); return; } if (n > DEFAULTBCNT) @@ -642,7 +680,7 @@ aoecmd_ata_id(struct aoedev *d) struct frame *f; struct sk_buff *skb; - f = getframe(d, FREETAG); + f = freeframe(d); if (f == NULL) { eprintk("can't get a frame. This shouldn't happen.\n"); return NULL; @@ -652,8 +690,8 @@ aoecmd_ata_id(struct aoedev *d) skb = f->skb; h = (struct aoe_hdr *) skb->mac.raw; ah = (struct aoe_atahdr *) (h+1); - skb->len = sizeof *h + sizeof *ah; - memset(h, 0, skb->len); + skb->len = ETH_ZLEN; + memset(h, 0, ETH_ZLEN); f->tag = aoehdr_atainit(d, h); f->waited = 0; @@ -663,12 +701,11 @@ aoecmd_ata_id(struct aoedev *d) ah->lba3 = 0xa0; skb->dev = d->ifp; - skb_get(skb); d->rttavg = MAXTIMER; d->timer.function = rexmit_timer; - return skb; + return skb_clone(skb, GFP_ATOMIC); } void @@ -724,7 +761,12 @@ aoecmd_cfg_rsp(struct sk_buff *skb) n /= 512; if (n > ch->scnt) n = ch->scnt; - d->maxbcnt = n ? n * 512 : DEFAULTBCNT; + n = n ? n * 512 : DEFAULTBCNT; + if (n != d->maxbcnt) { + iprintk("e%ld.%ld: setting %d byte data frames on %s\n", + d->aoemajor, d->aoeminor, n, d->ifp->name); + d->maxbcnt = n; + } } /* don't change users' perspective */ diff --git a/drivers/block/aoe/aoedev.c b/drivers/block/aoe/aoedev.c index f51d87bbb501..7fd63d4daf51 100644 --- a/drivers/block/aoe/aoedev.c +++ b/drivers/block/aoe/aoedev.c @@ -121,6 +121,7 @@ aoedev_downdev(struct aoedev *d) mempool_free(buf, d->bufpool); bio_endio(bio, bio->bi_size, -EIO); } + skb_shinfo(f->skb)->nr_frags = f->skb->data_len = 0; } d->inprocess = NULL;