From 69b91ede5cab843dcf345c28bd1f4b5a99dacd9b Mon Sep 17 00:00:00 2001 From: Bob Liu Date: Wed, 3 Jun 2015 13:40:01 +0800 Subject: [PATCH] drivers: xen-blkback: delay pending_req allocation to connect_ring This is a pre-patch for multi-page ring feature. In connect_ring, we can know exactly how many pages are used for the shared ring, delay pending_req allocation here so that we won't waste too much memory. Signed-off-by: Bob Liu Signed-off-by: Konrad Rzeszutek Wilk --- drivers/block/xen-blkback/common.h | 2 +- drivers/block/xen-blkback/xenbus.c | 82 ++++++++++++++---------------- 2 files changed, 39 insertions(+), 45 deletions(-) diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h index f620b5d3f77c..043f13b7b7b0 100644 --- a/drivers/block/xen-blkback/common.h +++ b/drivers/block/xen-blkback/common.h @@ -248,7 +248,7 @@ struct backend_info; #define PERSISTENT_GNT_WAS_ACTIVE 1 /* Number of requests that we can fit in a ring */ -#define XEN_BLKIF_REQS 32 +#define XEN_BLKIF_REQS_PER_PAGE 32 struct persistent_gnt { struct page *page; diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c index 6ab69ad61ee1..c212d41fd5bd 100644 --- a/drivers/block/xen-blkback/xenbus.c +++ b/drivers/block/xen-blkback/xenbus.c @@ -124,8 +124,6 @@ static void xen_update_blkif_status(struct xen_blkif *blkif) static struct xen_blkif *xen_blkif_alloc(domid_t domid) { struct xen_blkif *blkif; - struct pending_req *req, *n; - int i, j; BUILD_BUG_ON(MAX_INDIRECT_PAGES > BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST); @@ -151,51 +149,11 @@ static struct xen_blkif *xen_blkif_alloc(domid_t domid) INIT_LIST_HEAD(&blkif->pending_free); INIT_WORK(&blkif->free_work, xen_blkif_deferred_free); - - for (i = 0; i < XEN_BLKIF_REQS; i++) { - req = kzalloc(sizeof(*req), GFP_KERNEL); - if (!req) - goto fail; - list_add_tail(&req->free_list, - &blkif->pending_free); - for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) { - req->segments[j] = kzalloc(sizeof(*req->segments[0]), - GFP_KERNEL); - if (!req->segments[j]) - goto fail; - } - for (j = 0; j < MAX_INDIRECT_PAGES; j++) { - req->indirect_pages[j] = kzalloc(sizeof(*req->indirect_pages[0]), - GFP_KERNEL); - if (!req->indirect_pages[j]) - goto fail; - } - } spin_lock_init(&blkif->pending_free_lock); init_waitqueue_head(&blkif->pending_free_wq); init_waitqueue_head(&blkif->shutdown_wq); return blkif; - -fail: - list_for_each_entry_safe(req, n, &blkif->pending_free, free_list) { - list_del(&req->free_list); - for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) { - if (!req->segments[j]) - break; - kfree(req->segments[j]); - } - for (j = 0; j < MAX_INDIRECT_PAGES; j++) { - if (!req->indirect_pages[j]) - break; - kfree(req->indirect_pages[j]); - } - kfree(req); - } - - kmem_cache_free(xen_blkif_cachep, blkif); - - return ERR_PTR(-ENOMEM); } static int xen_blkif_map(struct xen_blkif *blkif, grant_ref_t gref, @@ -312,7 +270,7 @@ static void xen_blkif_free(struct xen_blkif *blkif) i++; } - WARN_ON(i != XEN_BLKIF_REQS); + WARN_ON(i != XEN_BLKIF_REQS_PER_PAGE); kmem_cache_free(xen_blkif_cachep, blkif); } @@ -864,7 +822,8 @@ static int connect_ring(struct backend_info *be) unsigned int evtchn; unsigned int pers_grants; char protocol[64] = ""; - int err; + struct pending_req *req, *n; + int err, i, j; pr_debug("%s %s\n", __func__, dev->otherend); @@ -905,6 +864,24 @@ static int connect_ring(struct backend_info *be) ring_ref, evtchn, be->blkif->blk_protocol, protocol, pers_grants ? "persistent grants" : ""); + for (i = 0; i < XEN_BLKIF_REQS_PER_PAGE; i++) { + req = kzalloc(sizeof(*req), GFP_KERNEL); + if (!req) + goto fail; + list_add_tail(&req->free_list, &be->blkif->pending_free); + for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) { + req->segments[j] = kzalloc(sizeof(*req->segments[0]), GFP_KERNEL); + if (!req->segments[j]) + goto fail; + } + for (j = 0; j < MAX_INDIRECT_PAGES; j++) { + req->indirect_pages[j] = kzalloc(sizeof(*req->indirect_pages[0]), + GFP_KERNEL); + if (!req->indirect_pages[j]) + goto fail; + } + } + /* Map the shared frame, irq etc. */ err = xen_blkif_map(be->blkif, ring_ref, evtchn); if (err) { @@ -914,6 +891,23 @@ static int connect_ring(struct backend_info *be) } return 0; + +fail: + list_for_each_entry_safe(req, n, &be->blkif->pending_free, free_list) { + list_del(&req->free_list); + for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) { + if (!req->segments[j]) + break; + kfree(req->segments[j]); + } + for (j = 0; j < MAX_INDIRECT_PAGES; j++) { + if (!req->indirect_pages[j]) + break; + kfree(req->indirect_pages[j]); + } + kfree(req); + } + return -ENOMEM; } static const struct xenbus_device_id xen_blkbk_ids[] = { -- 2.34.1