From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757955Ab2IDXYQ (ORCPT ); Tue, 4 Sep 2012 19:24:16 -0400 Received: from g1t0026.austin.hp.com ([15.216.28.33]:36096 "EHLO g1t0026.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757931Ab2IDXYO (ORCPT ); Tue, 4 Sep 2012 19:24:14 -0400 Message-ID: <1346801051.3130.31.camel@lorien2> Subject: Re: [PATCH] swiotlb: add kernel error message to track iobtlb overflow buffer usage From: Shuah Khan Reply-To: shuah.khan@hp.com To: konrad.wilk@oracle.com Cc: akpm@linux-foundation.org, paul.gortmaker@windriver.com, bhelgaas@google.com, amwang@redhat.com, linux-kernel@vger.kernel.org, fujita.tomonori@lab.ntt.co.jp, shuahkhan@gmail.com Date: Tue, 04 Sep 2012 17:24:11 -0600 In-Reply-To: <1346460959.3393.3.camel@lorien2> References: <1346460959.3393.3.camel@lorien2> Organization: ISS-Linux Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2012-08-31 at 18:55 -0600, Shuah Khan wrote: > Add kernel error message to track iotlb overflow buffer triggers to understand > how often the overflow buffer gets used. Does this change look reasonable? My intent is to be able to assess how often the overflow buffer usage gets triggered. -- Shuah > > Signed-off-by: Shuah Khan > --- > lib/swiotlb.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/lib/swiotlb.c b/lib/swiotlb.c > index 45bc1f8..597d7b9 100644 > --- a/lib/swiotlb.c > +++ b/lib/swiotlb.c > @@ -682,6 +682,7 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page, > if (!map) { > swiotlb_full(dev, size, dir, 1); > map = io_tlb_overflow_buffer; > + dev_err(dev, "SWIOTLB is full. Mapping overflow buffer.\n"); > } > > dev_addr = swiotlb_virt_to_bus(dev, map);