From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yk0-f171.google.com (mail-yk0-f171.google.com [209.85.160.171]) by kanga.kvack.org (Postfix) with ESMTP id 2C62D6B025B for ; Fri, 24 Jul 2015 08:15:20 -0400 (EDT) Received: by ykay190 with SMTP id y190so17816498yka.3 for ; Fri, 24 Jul 2015 05:15:20 -0700 (PDT) Received: from SMTP02.CITRIX.COM (smtp02.citrix.com. [66.165.176.63]) by mx.google.com with ESMTPS id b201si5935620ykb.20.2015.07.24.05.15.18 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Fri, 24 Jul 2015 05:15:19 -0700 (PDT) From: David Vrabel Subject: [PATCHv2 10/10] xen/balloon: pre-allocate p2m entries for ballooned pages Date: Fri, 24 Jul 2015 12:47:48 +0100 Message-ID: <1437738468-24110-11-git-send-email-david.vrabel@citrix.com> In-Reply-To: <1437738468-24110-1-git-send-email-david.vrabel@citrix.com> References: <1437738468-24110-1-git-send-email-david.vrabel@citrix.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: xen-devel@lists.xenproject.org Cc: David Vrabel , Konrad Rzeszutek Wilk , Boris Ostrovsky , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Daniel Kiper Pages returned by alloc_xenballooned_pages() will be used for grant mapping which will call set_phys_to_machine() (in PV guests). Ballooned pages are set as INVALID_P2M_ENTRY in the p2m and thus may be using the (shared) missing tables and a subsequent set_phys_to_machine() will need to allocate new tables. Since the grant mapping may be done from a context that cannot sleep, the p2m entries must already be allocated. Signed-off-by: David Vrabel --- drivers/xen/balloon.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index fd6970f3..8932d10 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -541,6 +541,7 @@ int alloc_xenballooned_pages(int nr_pages, struct page **pages) { int pgno = 0; struct page *page; + int ret = -ENOMEM; mutex_lock(&balloon_mutex); @@ -550,6 +551,11 @@ int alloc_xenballooned_pages(int nr_pages, struct page **pages) page = balloon_retrieve(true); if (page) { pages[pgno++] = page; +#ifdef CONFIG_XEN_HAVE_PVMMU + ret = xen_alloc_p2m_entry(page_to_pfn(page)); + if (ret < 0) + goto out_undo; +#endif } else { enum bp_state st; @@ -576,7 +582,7 @@ int alloc_xenballooned_pages(int nr_pages, struct page **pages) out_undo: mutex_unlock(&balloon_mutex); free_xenballooned_pages(pgno, pages); - return -ENOMEM; + return ret; } EXPORT_SYMBOL(alloc_xenballooned_pages); -- 2.1.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org