Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-ig0-f171.google.com ([209.85.213.171]:57033 "EHLO mail-ig0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754267AbaHGLFY (ORCPT ); Thu, 7 Aug 2014 07:05:24 -0400 Received: by mail-ig0-f171.google.com with SMTP id l13so10170797iga.16 for ; Thu, 07 Aug 2014 04:05:23 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1407396229-4785-18-git-send-email-hch@lst.de> References: <1407396229-4785-1-git-send-email-hch@lst.de> <1407396229-4785-18-git-send-email-hch@lst.de> From: Peng Tao Date: Thu, 7 Aug 2014 19:05:03 +0800 Message-ID: Subject: Re: [PATCH 17/17] pnfs/blocklayout: allocate separate pages for the layoutcommit payload To: Christoph Hellwig Cc: Trond Myklebust , linuxnfs Content-Type: text/plain; charset=UTF-8 Sender: linux-nfs-owner@vger.kernel.org List-ID: On Thu, Aug 7, 2014 at 3:23 PM, Christoph Hellwig wrote: > Instead of overflowing the XDR send buffer with our extent list allocate > pages and pre-encode the layoutupdate payload into them. We optimistically > allocate a single page use alloc_page and only switch to vmalloc when we > have more extents outstanding. Currently there is only a single testcase > (xfstests generic/113) which can reproduce large enough extent lists for > this to occur. > depending on how badly the extents are fragmented, it might worth starting an async layoutcommit within blocklayout client when bl_count reaches certain limit, so that we don't send an unlimited amount of extents in one layoutcommit. Cheers, Tao > Signed-off-by: Christoph Hellwig > --- > fs/nfs/blocklayout/blocklayout.c | 9 ++-- > fs/nfs/blocklayout/blocklayout.h | 6 ++- > fs/nfs/blocklayout/extent_tree.c | 89 +++++++++++++++++++++++++++++++--------- > 3 files changed, 78 insertions(+), 26 deletions(-) > > diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c > index d5a2b87..fae8144 100644 > --- a/fs/nfs/blocklayout/blocklayout.c > +++ b/fs/nfs/blocklayout/blocklayout.c > @@ -498,12 +498,11 @@ bl_return_range(struct pnfs_layout_hdr *lo, > err = ext_tree_remove(bl, range->iomode & IOMODE_RW, offset, end); > } > > -static void > -bl_encode_layoutcommit(struct pnfs_layout_hdr *lo, struct xdr_stream *xdr, > - const struct nfs4_layoutcommit_args *arg) > +static int > +bl_prepare_layoutcommit(struct nfs4_layoutcommit_args *arg) > { > dprintk("%s enter\n", __func__); > - ext_tree_encode_commit(BLK_LO2EXT(lo), xdr); > + return ext_tree_prepare_commit(arg); > } > > static void > @@ -808,7 +807,7 @@ static struct pnfs_layoutdriver_type blocklayout_type = { > .alloc_lseg = bl_alloc_lseg, > .free_lseg = bl_free_lseg, > .return_range = bl_return_range, > - .encode_layoutcommit = bl_encode_layoutcommit, > + .prepare_layoutcommit = bl_prepare_layoutcommit, > .cleanup_layoutcommit = bl_cleanup_layoutcommit, > .set_layoutdriver = bl_set_layoutdriver, > .clear_layoutdriver = bl_clear_layoutdriver, > diff --git a/fs/nfs/blocklayout/blocklayout.h b/fs/nfs/blocklayout/blocklayout.h > index b4f66d8..caae202 100644 > --- a/fs/nfs/blocklayout/blocklayout.h > +++ b/fs/nfs/blocklayout/blocklayout.h > @@ -80,6 +80,9 @@ struct pnfs_block_extent { > unsigned int be_tag; > }; > > +/* on the wire size of the extent */ > +#define BL_EXTENT_SIZE (7 * sizeof(__be32) + NFS4_DEVICEID4_SIZE) > + > struct pnfs_block_layout { > struct pnfs_layout_hdr bl_layout; > struct rb_root bl_ext_rw; > @@ -138,8 +141,7 @@ int ext_tree_mark_written(struct pnfs_block_layout *bl, sector_t start, > sector_t len); > bool ext_tree_lookup(struct pnfs_block_layout *bl, sector_t isect, > struct pnfs_block_extent *ret, bool rw); > -int ext_tree_encode_commit(struct pnfs_block_layout *bl, > - struct xdr_stream *xdr); > +int ext_tree_prepare_commit(struct nfs4_layoutcommit_args *arg); > void ext_tree_mark_committed(struct pnfs_block_layout *bl, int status); > > #endif /* FS_NFS_NFS4BLOCKLAYOUT_H */ > diff --git a/fs/nfs/blocklayout/extent_tree.c b/fs/nfs/blocklayout/extent_tree.c > index c7dacfa..3945221 100644 > --- a/fs/nfs/blocklayout/extent_tree.c > +++ b/fs/nfs/blocklayout/extent_tree.c > @@ -465,32 +465,23 @@ out: > return err; > } > > -int > -ext_tree_encode_commit(struct pnfs_block_layout *bl, struct xdr_stream *xdr) > +static int ext_tree_encode_commit(struct pnfs_block_layout *bl, __be32 *p, > + size_t buffer_size, size_t *count) > { > struct pnfs_block_extent *be; > - unsigned int count = 0; > - __be32 *p, *xdr_start; > int ret = 0; > > - dprintk("%s enter\n", __func__); > - > - xdr_start = xdr_reserve_space(xdr, 8); > - if (!xdr_start) > - return -ENOSPC; > - > spin_lock(&bl->bl_ext_lock); > for (be = ext_tree_first(&bl->bl_ext_rw); be; be = ext_tree_next(be)) { > if (be->be_state != PNFS_BLOCK_INVALID_DATA || > be->be_tag != EXTENT_WRITTEN) > continue; > > - p = xdr_reserve_space(xdr, 7 * sizeof(__be32) + > - NFS4_DEVICEID4_SIZE); > - if (!p) { > - printk("%s: out of space for extent list\n", __func__); > + (*count)++; > + if (*count * BL_EXTENT_SIZE > buffer_size) { > + /* keep counting.. */ > ret = -ENOSPC; > - break; > + continue; > } > > p = xdr_encode_opaque_fixed(p, be->be_devid.data, > @@ -501,15 +492,75 @@ ext_tree_encode_commit(struct pnfs_block_layout *bl, struct xdr_stream *xdr) > *p++ = cpu_to_be32(PNFS_BLOCK_READWRITE_DATA); > > be->be_tag = EXTENT_COMMITTING; > - count++; > } > spin_unlock(&bl->bl_ext_lock); > > - xdr_start[0] = cpu_to_be32((xdr->p - xdr_start - 1) * 4); > - xdr_start[1] = cpu_to_be32(count); > + return ret; > +} > + > +int > +ext_tree_prepare_commit(struct nfs4_layoutcommit_args *arg) > +{ > + struct pnfs_block_layout *bl = BLK_LO2EXT(NFS_I(arg->inode)->layout); > + size_t count = 0, buffer_size = PAGE_SIZE; > + __be32 *start_p; > + int ret; > + > + dprintk("%s enter\n", __func__); > + > + arg->layoutupdate_page = alloc_page(GFP_NOFS); > + if (!arg->layoutupdate_page) > + return -ENOMEM; > + start_p = page_address(arg->layoutupdate_page); > + arg->layoutupdate_pages = &arg->layoutupdate_page; > + > +retry: > + ret = ext_tree_encode_commit(bl, start_p + 1, buffer_size, &count); > + if (unlikely(ret)) { > + if (arg->layoutupdate_pages != &arg->layoutupdate_page) { > + int nr_pages = DIV_ROUND_UP(buffer_size, PAGE_SIZE), i; > + > + for (i = 0; i < nr_pages; i++) > + put_page(arg->layoutupdate_pages[i]); > + kfree(arg->layoutupdate_pages); > + } else { > + put_page(arg->layoutupdate_page); > + } > + > + buffer_size = sizeof(__be32) + BL_EXTENT_SIZE * count; > + count = 0; > + > + arg->layoutupdate_pages = > + kcalloc(DIV_ROUND_UP(buffer_size, PAGE_SIZE), > + sizeof(struct page *), GFP_NOFS); > + if (!arg->layoutupdate_pages) > + return -ENOMEM; > + > + start_p = __vmalloc(buffer_size, GFP_NOFS, PAGE_KERNEL); > + if (!start_p) { > + kfree(arg->layoutupdate_pages); > + return -ENOMEM; > + } > + > + goto retry; > + } > + > + *start_p = cpu_to_be32(count); > + arg->layoutupdate_len = sizeof(__be32) + BL_EXTENT_SIZE * count; > + > + if (unlikely(arg->layoutupdate_pages != &arg->layoutupdate_page)) { > + __be32 *p = start_p; > + int i = 0; > + > + for (p = start_p; > + p < start_p + arg->layoutupdate_len; > + p += PAGE_SIZE) { > + arg->layoutupdate_pages[i++] = vmalloc_to_page(p); > + } > + } > > dprintk("%s found %i ranges\n", __func__, count); > - return ret; > + return 0; > } > > void > -- > 1.9.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html