lkml.org 
[lkml]   [2006]   [Sep]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    Subject[PATCH 2.6.18-rc4] aoe [09/14]: zero copy write 2 of 2
    From
    Avoid memory copy on writes.
    (This patch follows patch 4.)

    Signed-off-by: "Ed L. Cashin" <ecashin@coraid.com>
    ---

    diff -upr 2.6.18-rc4-orig/drivers/block/aoe/aoe.h 2.6.18-rc4-aoe/drivers/block/aoe/aoe.h
    --- 2.6.18-rc4-orig/drivers/block/aoe/aoe.h 2006-09-20 14:29:36.000000000 -0400
    +++ 2.6.18-rc4-aoe/drivers/block/aoe/aoe.h 2006-09-20 14:29:36.000000000 -0400
    @@ -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 -upr 2.6.18-rc4-orig/drivers/block/aoe/aoecmd.c 2.6.18-rc4-aoe/drivers/block/aoe/aoecmd.c
    --- 2.6.18-rc4-orig/drivers/block/aoe/aoecmd.c 2006-09-20 14:29:36.000000000 -0400
    +++ 2.6.18-rc4-aoe/drivers/block/aoe/aoecmd.c 2006-09-20 14:29:36.000000000 -0400
    @@ -120,7 +120,7 @@ aoecmd_ata_rw(struct aoedev *d, struct 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 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 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, unsigne
    return sl;
    }

    +static struct frame *
    +freeframe(struct aoedev *d)
    +{
    + struct frame *f, *e;
    + int n = 0;
    +
    + f = d->frames;
    + e = f + d->nframes;
    + for (; f<e; f++) {
    + if (f->tag != 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 -upr 2.6.18-rc4-orig/drivers/block/aoe/aoedev.c 2.6.18-rc4-aoe/drivers/block/aoe/aoedev.c
    --- 2.6.18-rc4-orig/drivers/block/aoe/aoedev.c 2006-09-20 14:29:35.000000000 -0400
    +++ 2.6.18-rc4-aoe/drivers/block/aoe/aoedev.c 2006-09-20 14:29:36.000000000 -0400
    @@ -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;


    --
    "Ed L. Cashin" <ecashin@coraid.com>
    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2006-09-20 21:01    [W:4.937 / U:0.004 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site