Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751359AbbEZAG2 (ORCPT ); Mon, 25 May 2015 20:06:28 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:37084 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751045AbbEZAGY (ORCPT ); Mon, 25 May 2015 20:06:24 -0400 From: Bob Liu To: xen-devel@lists.xen.org Cc: david.vrabel@citrix.com, justing@spectralogic.com, konrad.wilk@oracle.com, roger.pau@citrix.com, paul.durrant@citrix.com, julien.grall@citrix.com, boris.ostrovsky@oracle.com, linux-kernel@vger.kernel.org, Bob Liu Subject: [PATCH] drivers: xen-blkback: delay pending_req allocation to connect_ring Date: Tue, 26 May 2015 08:06:04 +0800 Message-Id: <1432598764-21546-1-git-send-email-bob.liu@oracle.com> X-Mailer: git-send-email 1.7.10.4 X-Source-IP: userv0022.oracle.com [156.151.31.74] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6077 Lines: 198 In connect_ring, we can know exactly how many pages are used for the shared ring and also whether feature-persistent is enabled, delay pending_req allocation here so that we won't waste too much memory. Signed-off-by: Bob Liu --- drivers/block/xen-blkback/common.h | 3 +- drivers/block/xen-blkback/xenbus.c | 95 ++++++++++++++++++++------------------ 2 files changed, 51 insertions(+), 47 deletions(-) diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h index 919a1ab..e1d605d 100644 --- a/drivers/block/xen-blkback/common.h +++ b/drivers/block/xen-blkback/common.h @@ -249,7 +249,7 @@ struct backend_info; #define PERSISTENT_GNT_WAS_ACTIVE 1 /* Number of requests that we can fit in a ring */ -#define XEN_MAX_BLKIF_REQS (32 * XENBUS_MAX_RING_PAGES) +#define XEN_BLKIF_REQS 32 struct persistent_gnt { struct page *page; @@ -321,6 +321,7 @@ struct xen_blkif { struct work_struct free_work; /* Thread shutdown wait queue. */ wait_queue_head_t shutdown_wq; + unsigned int nr_ring_pages; }; struct seg_buf { diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c index bc33888..48336a3 100644 --- a/drivers/block/xen-blkback/xenbus.c +++ b/drivers/block/xen-blkback/xenbus.c @@ -125,8 +125,6 @@ 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); @@ -153,50 +151,11 @@ 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_MAX_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, @@ -313,7 +272,7 @@ static void xen_blkif_free(struct xen_blkif *blkif) i++; } - WARN_ON(i != XEN_MAX_BLKIF_REQS); + WARN_ON(i != XEN_BLKIF_REQS * blkif->nr_ring_pages); kmem_cache_free(xen_blkif_cachep, blkif); } @@ -868,9 +827,10 @@ static int connect_ring(struct backend_info *be) struct xenbus_device *dev = be->dev; unsigned int ring_ref[XENBUS_MAX_RING_PAGES]; unsigned int evtchn, nr_grefs, ring_page_order; - unsigned int pers_grants; + unsigned int pers_grants, i, j; + struct pending_req *req, *n; char protocol[64] = ""; - int err; + int err, nr_indiret_pages, nr_segs; pr_debug("%s %s\n", __func__, dev->otherend); @@ -899,8 +859,6 @@ static int connect_ring(struct backend_info *be) pr_info("%s:using single page: ring-ref %d\n", dev->otherend, ring_ref[0]); } else { - unsigned int i; - if (ring_page_order > xen_blkif_max_ring_order) { err = -EINVAL; xenbus_dev_fatal(dev, err, "%s/request %d ring page order exceed max:%d", @@ -949,11 +907,39 @@ static int connect_ring(struct backend_info *be) be->blkif->vbd.feature_gnt_persistent = pers_grants; be->blkif->vbd.overflow_max_grants = 0; + be->blkif->nr_ring_pages = nr_grefs; pr_info("ring-pages:%d, event-channel %d, protocol %d (%s) %s\n", nr_grefs, evtchn, be->blkif->blk_protocol, protocol, pers_grants ? "persistent grants" : ""); + if (!pers_grants) { + nr_indiret_pages = 0; + nr_segs = BLKIF_MAX_SEGMENTS_PER_REQUEST; + } else { + nr_indiret_pages = MAX_INDIRECT_PAGES; + nr_segs = MAX_INDIRECT_SEGMENTS; + } + + for (i = 0; i < nr_grefs * XEN_BLKIF_REQS; 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 < nr_segs; j++) { + req->segments[j] = kzalloc(sizeof(*req->segments[0]), + GFP_KERNEL); + if (!req->segments[j]) + goto fail; + } + for (j = 0; j < nr_indiret_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, nr_grefs, evtchn); if (err) { @@ -962,6 +948,23 @@ 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[] = { -- 1.8.3.1 -- 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/