From 3d5b06051cd5fa82c9a4285f7ce8650a0f0845ff Mon Sep 17 00:00:00 2001 From: Ed Cashin Date: Thu, 4 Oct 2012 17:16:20 -0700 Subject: [PATCH] aoe: for performance support larger packet payloads tAdd adds the ability to work with large packets composed of a number of segments, using the scatter gather feature of the block layer (biovecs) and the network layer (skb frag array). The motivation is the performance gained by using a packet data payload greater than a page size and by using the network card's scatter gather feature. Users of the out-of-tree aoe driver already had these changes, but since early 2011, they have complained of increased memory utilization and higher CPU utilization during heavy writes.[1] The commit below appears related, as it disables scatter gather on non-IP protocols inside the harmonize_features function, even when the NIC supports sg. commit f01a5236bd4b140198fbcc550f085e8361fd73fa Author: Jesse Gross Date: Sun Jan 9 06:23:31 2011 +0000 net offloading: Generalize netif_get_vlan_features(). With that regression in place, transmits always linearize sg AoE packets, but in-kernel users did not have this patch. Before 2.6.38, though, these changes were working to allow sg to increase performance. 1. http://www.spinics.net/lists/linux-mm/msg15184.html Signed-off-by: Ed Cashin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/block/aoe/aoe.h | 2 + drivers/block/aoe/aoeblk.c | 3 + drivers/block/aoe/aoecmd.c | 138 ++++++++++++++++++++++++++----------- drivers/block/aoe/aoedev.c | 1 + drivers/block/aoe/aoenet.c | 13 ++-- 5 files changed, 111 insertions(+), 46 deletions(-) diff --git a/drivers/block/aoe/aoe.h b/drivers/block/aoe/aoe.h index db195abad69..8ca8c8a929a 100644 --- a/drivers/block/aoe/aoe.h +++ b/drivers/block/aoe/aoe.h @@ -119,6 +119,8 @@ struct frame { ulong bcnt; sector_t lba; struct sk_buff *skb; + struct bio_vec *bv; + ulong bv_off; }; struct aoeif { diff --git a/drivers/block/aoe/aoeblk.c b/drivers/block/aoe/aoeblk.c index 321de7b6c44..3a8f0933cc7 100644 --- a/drivers/block/aoe/aoeblk.c +++ b/drivers/block/aoe/aoeblk.c @@ -254,6 +254,7 @@ aoeblk_gdalloc(void *vp) { struct aoedev *d = vp; struct gendisk *gd; + enum { KB = 1024, MB = KB * KB, READ_AHEAD = MB, }; ulong flags; gd = alloc_disk(AOE_PARTITIONS); @@ -279,6 +280,8 @@ aoeblk_gdalloc(void *vp) if (bdi_init(&d->blkq->backing_dev_info)) goto err_blkq; spin_lock_irqsave(&d->lock, flags); + blk_queue_max_hw_sectors(d->blkq, BLK_DEF_MAX_SECTORS); + d->blkq->backing_dev_info.ra_pages = READ_AHEAD / PAGE_CACHE_SIZE; gd->major = AOE_MAJOR; gd->first_minor = d->sysminor * AOE_PARTITIONS; gd->fops = &aoe_bdops; diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c index 887f68f6d79..9a58242290c 100644 --- a/drivers/block/aoe/aoecmd.c +++ b/drivers/block/aoe/aoecmd.c @@ -165,7 +165,8 @@ freeframe(struct aoedev *d) rf = f; continue; } -gotone: skb_shinfo(skb)->nr_frags = skb->data_len = 0; +gotone: skb->truesize -= skb->data_len; + skb_shinfo(skb)->nr_frags = skb->data_len = 0; skb_trim(skb, 0); d->tgt = t; ifrotate(*t); @@ -201,6 +202,24 @@ gotone: skb_shinfo(skb)->nr_frags = skb->data_len = 0; return NULL; } +static void +skb_fillup(struct sk_buff *skb, struct bio_vec *bv, ulong off, ulong cnt) +{ + int frag = 0; + ulong fcnt; +loop: + fcnt = bv->bv_len - (off - bv->bv_offset); + if (fcnt > cnt) + fcnt = cnt; + skb_fill_page_desc(skb, frag++, bv->bv_page, off, fcnt); + cnt -= fcnt; + if (cnt <= 0) + return; + bv++; + off = bv->bv_offset; + goto loop; +} + static int aoecmd_ata_rw(struct aoedev *d) { @@ -211,7 +230,7 @@ aoecmd_ata_rw(struct aoedev *d) struct bio_vec *bv; struct aoetgt *t; struct sk_buff *skb; - ulong bcnt; + ulong bcnt, fbcnt; char writebit, extbit; writebit = 0x10; @@ -226,8 +245,28 @@ aoecmd_ata_rw(struct aoedev *d) bcnt = t->ifp->maxbcnt; if (bcnt == 0) bcnt = DEFAULTBCNT; - if (bcnt > buf->bv_resid) - bcnt = buf->bv_resid; + if (bcnt > buf->resid) + bcnt = buf->resid; + fbcnt = bcnt; + f->bv = buf->bv; + f->bv_off = f->bv->bv_offset + (f->bv->bv_len - buf->bv_resid); + do { + if (fbcnt < buf->bv_resid) { + buf->bv_resid -= fbcnt; + buf->resid -= fbcnt; + break; + } + fbcnt -= buf->bv_resid; + buf->resid -= buf->bv_resid; + if (buf->resid == 0) { + d->inprocess = NULL; + break; + } + buf->bv++; + buf->bv_resid = buf->bv->bv_len; + WARN_ON(buf->bv_resid == 0); + } while (fbcnt); + /* initialize the headers & frame */ skb = f->skb; h = (struct aoe_hdr *) skb_mac_header(skb); @@ -238,7 +277,6 @@ aoecmd_ata_rw(struct aoedev *d) t->nout++; f->waited = 0; f->buf = buf; - f->bufaddr = page_address(bv->bv_page) + buf->bv_off; f->bcnt = bcnt; f->lba = buf->sector; @@ -253,10 +291,11 @@ aoecmd_ata_rw(struct aoedev *d) ah->lba3 |= 0xe0; /* LBA bit + obsolete 0xa0 */ } if (bio_data_dir(buf->bio) == WRITE) { - skb_fill_page_desc(skb, 0, bv->bv_page, buf->bv_off, bcnt); + skb_fillup(skb, f->bv, f->bv_off, bcnt); ah->aflags |= AOEAFL_WRITE; skb->len += bcnt; skb->data_len = bcnt; + skb->truesize += bcnt; t->wpkts++; } else { t->rpkts++; @@ -267,18 +306,7 @@ aoecmd_ata_rw(struct aoedev *d) /* mark all tracking fields and load out */ buf->nframesout += 1; - buf->bv_off += bcnt; - buf->bv_resid -= bcnt; - buf->resid -= bcnt; buf->sector += bcnt >> 9; - if (buf->resid == 0) { - d->inprocess = NULL; - } else if (buf->bv_resid == 0) { - buf->bv = ++bv; - buf->bv_resid = bv->bv_len; - WARN_ON(buf->bv_resid == 0); - buf->bv_off = bv->bv_offset; - } skb->dev = t->ifp->nd; skb = skb_clone(skb, GFP_ATOMIC); @@ -365,14 +393,12 @@ resend(struct aoedev *d, struct aoetgt *t, struct frame *f) put_lba(ah, f->lba); n = f->bcnt; - if (n > DEFAULTBCNT) - n = DEFAULTBCNT; ah->scnt = n >> 9; if (ah->aflags & AOEAFL_WRITE) { - skb_fill_page_desc(skb, 0, virt_to_page(f->bufaddr), - offset_in_page(f->bufaddr), n); + skb_fillup(skb, f->bv, f->bv_off, n); skb->len = sizeof *h + sizeof *ah + n; skb->data_len = n; + skb->truesize += n; } } skb->dev = t->ifp->nd; @@ -531,20 +557,6 @@ rexmit_timer(ulong vp) ejectif(t, ifp); ifp = NULL; } - - if (ata_scnt(skb_mac_header(f->skb)) > DEFAULTBCNT / 512 - && ifp && ++ifp->lostjumbo > (t->nframes << 1) - && ifp->maxbcnt != DEFAULTBCNT) { - printk(KERN_INFO - "aoe: e%ld.%d: " - "too many lost jumbo on " - "%s:%pm - " - "falling back to %d frames.\n", - d->aoemajor, d->aoeminor, - ifp->nd->name, t->addr, - DEFAULTBCNT); - ifp->maxbcnt = 0; - } resend(d, t, f); } @@ -737,6 +749,45 @@ diskstats(struct gendisk *disk, struct bio *bio, ulong duration, sector_t sector part_stat_unlock(); } +static void +bvcpy(struct bio_vec *bv, ulong off, struct sk_buff *skb, ulong cnt) +{ + ulong fcnt; + char *p; + int soff = 0; +loop: + fcnt = bv->bv_len - (off - bv->bv_offset); + if (fcnt > cnt) + fcnt = cnt; + p = page_address(bv->bv_page) + off; + skb_copy_bits(skb, soff, p, fcnt); + soff += fcnt; + cnt -= fcnt; + if (cnt <= 0) + return; + bv++; + off = bv->bv_offset; + goto loop; +} + +static void +fadvance(struct frame *f, ulong cnt) +{ + ulong fcnt; + + f->lba += cnt >> 9; +loop: + fcnt = f->bv->bv_len - (f->bv_off - f->bv->bv_offset); + if (fcnt > cnt) { + f->bv_off += cnt; + return; + } + cnt -= fcnt; + f->bv++; + f->bv_off = f->bv->bv_offset; + goto loop; +} + void aoecmd_ata_rsp(struct sk_buff *skb) { @@ -754,6 +805,7 @@ aoecmd_ata_rsp(struct sk_buff *skb) u16 aoemajor; hin = (struct aoe_hdr *) skb_mac_header(skb); + skb_pull(skb, sizeof(*hin)); aoemajor = get_unaligned_be16(&hin->major); d = aoedev_by_aoeaddr(aoemajor, hin->minor); if (d == NULL) { @@ -791,7 +843,8 @@ aoecmd_ata_rsp(struct sk_buff *skb) calc_rttavg(d, tsince(f->tag)); - ahin = (struct aoe_atahdr *) (hin+1); + ahin = (struct aoe_atahdr *) skb->data; + skb_pull(skb, sizeof(*ahin)); hout = (struct aoe_hdr *) skb_mac_header(f->skb); ahout = (struct aoe_atahdr *) (hout+1); buf = f->buf; @@ -810,7 +863,7 @@ aoecmd_ata_rsp(struct sk_buff *skb) switch (ahout->cmdstat) { case ATA_CMD_PIO_READ: case ATA_CMD_PIO_READ_EXT: - if (skb->len - sizeof *hin - sizeof *ahin < n) { + if (skb->len < n) { printk(KERN_ERR "aoe: %s. skb->len=%d need=%ld\n", "runt data size in read", skb->len, n); @@ -818,7 +871,7 @@ aoecmd_ata_rsp(struct sk_buff *skb) spin_unlock_irqrestore(&d->lock, flags); return; } - memcpy(f->bufaddr, ahin+1, n); + bvcpy(f->bv, f->bv_off, skb, n); case ATA_CMD_PIO_WRITE: case ATA_CMD_PIO_WRITE_EXT: ifp = getif(t, skb->dev); @@ -828,21 +881,22 @@ aoecmd_ata_rsp(struct sk_buff *skb) ifp->lostjumbo = 0; } if (f->bcnt -= n) { - f->lba += n >> 9; - f->bufaddr += n; + fadvance(f, n); resend(d, t, f); goto xmit; } break; case ATA_CMD_ID_ATA: - if (skb->len - sizeof *hin - sizeof *ahin < 512) { + if (skb->len < 512) { printk(KERN_INFO "aoe: runt data size in ataid. skb->len=%d\n", skb->len); spin_unlock_irqrestore(&d->lock, flags); return; } - ataid_complete(d, t, (char *) (ahin+1)); + if (skb_linearize(skb)) + break; + ataid_complete(d, t, skb->data); break; default: printk(KERN_INFO diff --git a/drivers/block/aoe/aoedev.c b/drivers/block/aoe/aoedev.c index 6b5110a4745..b2d1fd354ea 100644 --- a/drivers/block/aoe/aoedev.c +++ b/drivers/block/aoe/aoedev.c @@ -182,6 +182,7 @@ skbfree(struct sk_buff *skb) "cannot free skb -- memory leaked."); return; } + skb->truesize -= skb->data_len; skb_shinfo(skb)->nr_frags = skb->data_len = 0; skb_trim(skb, 0); dev_kfree_skb(skb); diff --git a/drivers/block/aoe/aoenet.c b/drivers/block/aoe/aoenet.c index 4d3bc0d49df..07878076e43 100644 --- a/drivers/block/aoe/aoenet.c +++ b/drivers/block/aoe/aoenet.c @@ -102,7 +102,9 @@ static int aoenet_rcv(struct sk_buff *skb, struct net_device *ifp, struct packet_type *pt, struct net_device *orig_dev) { struct aoe_hdr *h; + struct aoe_atahdr *ah; u32 n; + int sn; if (dev_net(ifp) != &init_net) goto exit; @@ -110,13 +112,16 @@ aoenet_rcv(struct sk_buff *skb, struct net_device *ifp, struct packet_type *pt, skb = skb_share_check(skb, GFP_ATOMIC); if (skb == NULL) return 0; - if (skb_linearize(skb)) - goto exit; if (!is_aoe_netif(ifp)) goto exit; skb_push(skb, ETH_HLEN); /* (1) */ - - h = (struct aoe_hdr *) skb_mac_header(skb); + sn = sizeof(*h) + sizeof(*ah); + if (skb->len >= sn) { + sn -= skb_headlen(skb); + if (sn > 0 && !__pskb_pull_tail(skb, sn)) + goto exit; + } + h = (struct aoe_hdr *) skb->data; n = get_unaligned_be32(&h->tag); if ((h->verfl & AOEFL_RSP) == 0 || (n & 1<<31)) goto exit; -- 2.20.1