Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753864AbbGIUtr (ORCPT ); Thu, 9 Jul 2015 16:49:47 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:58745 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754055AbbGIUnk (ORCPT ); Thu, 9 Jul 2015 16:43:40 -0400 X-IronPort-AV: E=Sophos;i="5.15,442,1432598400"; d="scan'208";a="282741506" From: Julien Grall To: CC: , , , , "Julien Grall" , Konrad Rzeszutek Wilk , Boris Ostrovsky , "David Vrabel" Subject: [PATCH v2 09/20] xen/biomerge: Don't allow biovec to be merge when Linux is not using 4KB page Date: Thu, 9 Jul 2015 21:42:21 +0100 Message-ID: <1436474552-31789-10-git-send-email-julien.grall@citrix.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1436474552-31789-1-git-send-email-julien.grall@citrix.com> References: <1436474552-31789-1-git-send-email-julien.grall@citrix.com> MIME-Version: 1.0 Content-Type: text/plain X-DLP: MIA1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1634 Lines: 49 When Linux is using 64K page granularity, every page will be slipt in multiple non-contiguous 4K MFN (page granularity of Xen). I'm not sure how to handle efficiently the check to know whether we can merge 2 biovec with a such case. So for now, always says that biovec are not mergeable. Signed-off-by: Julien Grall Cc: Konrad Rzeszutek Wilk Cc: Boris Ostrovsky Cc: David Vrabel --- Changes in v2: - Remove the workaround and check if the Linux page granularity is the same as Xen or not --- drivers/xen/biomerge.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/xen/biomerge.c b/drivers/xen/biomerge.c index 0edb91c..571567c 100644 --- a/drivers/xen/biomerge.c +++ b/drivers/xen/biomerge.c @@ -6,10 +6,17 @@ bool xen_biovec_phys_mergeable(const struct bio_vec *vec1, const struct bio_vec *vec2) { +#if XEN_PAGE_SIZE == PAGE_SIZE unsigned long mfn1 = pfn_to_mfn(page_to_pfn(vec1->bv_page)); unsigned long mfn2 = pfn_to_mfn(page_to_pfn(vec2->bv_page)); return __BIOVEC_PHYS_MERGEABLE(vec1, vec2) && ((mfn1 == mfn2) || ((mfn1+1) == mfn2)); +#else + /* XXX: bio_vec are not mergeable when using different page size in + * Xen and Linux + */ + return 0; +#endif } EXPORT_SYMBOL(xen_biovec_phys_mergeable); -- 2.1.4 -- 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/