From 3da28eb1c6545fe73263a24eba0996217490e1eb Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Wed, 22 Jun 2005 17:16:31 +0000 Subject: [PATCH] NFS: Replace nfs_page insertion sort with a radix sort Signed-off-by: Trond Myklebust --- fs/nfs/pagelist.c | 86 ++++++++++++++++++++++++++++++++++++------------------- 1 file changed, 56 insertions(+), 30 deletions(-) (limited to 'fs/nfs/pagelist.c') diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index 356a33bb38a..d53857b148e 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -177,36 +177,6 @@ nfs_release_request(struct nfs_page *req) nfs_page_free(req); } -/** - * nfs_list_add_request - Insert a request into a sorted list - * @req: request - * @head: head of list into which to insert the request. - * - * Note that the wb_list is sorted by page index in order to facilitate - * coalescing of requests. - * We use an insertion sort that is optimized for the case of appended - * writes. - */ -void -nfs_list_add_request(struct nfs_page *req, struct list_head *head) -{ - struct list_head *pos; - -#ifdef NFS_PARANOIA - if (!list_empty(&req->wb_list)) { - printk(KERN_ERR "NFS: Add to list failed!\n"); - BUG(); - } -#endif - list_for_each_prev(pos, head) { - struct nfs_page *p = nfs_list_entry(pos); - if (p->wb_index < req->wb_index) - break; - } - list_add(&req->wb_list, pos); - req->wb_list_head = head; -} - static int nfs_wait_bit_interruptible(void *word) { int ret = 0; @@ -291,6 +261,62 @@ nfs_coalesce_requests(struct list_head *head, struct list_head *dst, return npages; } +#define NFS_SCAN_MAXENTRIES 16 +/** + * nfs_scan_lock_dirty - Scan the radix tree for dirty requests + * @nfsi: NFS inode + * @dst: Destination list + * @idx_start: lower bound of page->index to scan + * @npages: idx_start + npages sets the upper bound to scan. + * + * Moves elements from one of the inode request lists. + * If the number of requests is set to 0, the entire address_space + * starting at index idx_start, is scanned. + * The requests are *not* checked to ensure that they form a contiguous set. + * You must be holding the inode's req_lock when calling this function + */ +int +nfs_scan_lock_dirty(struct nfs_inode *nfsi, struct list_head *dst, + unsigned long idx_start, unsigned int npages) +{ + struct nfs_page *pgvec[NFS_SCAN_MAXENTRIES]; + struct nfs_page *req; + unsigned long idx_end; + int found, i; + int res; + + res = 0; + if (npages == 0) + idx_end = ~0; + else + idx_end = idx_start + npages - 1; + + for (;;) { + found = radix_tree_gang_lookup_tag(&nfsi->nfs_page_tree, + (void **)&pgvec[0], idx_start, NFS_SCAN_MAXENTRIES, + NFS_PAGE_TAG_DIRTY); + if (found <= 0) + break; + for (i = 0; i < found; i++) { + req = pgvec[i]; + if (req->wb_index > idx_end) + goto out; + + idx_start = req->wb_index + 1; + + if (nfs_set_page_writeback_locked(req)) { + radix_tree_tag_clear(&nfsi->nfs_page_tree, + req->wb_index, NFS_PAGE_TAG_DIRTY); + nfs_list_remove_request(req); + nfs_list_add_request(req, dst); + res++; + } + } + } +out: + return res; +} + /** * nfs_scan_list - Scan a list for matching requests * @head: One of the NFS inode request lists -- cgit v1.2.2