Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754010Ab3JCI1O (ORCPT ); Thu, 3 Oct 2013 04:27:14 -0400 Received: from mail-ea0-f170.google.com ([209.85.215.170]:50089 "EHLO mail-ea0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753952Ab3JCI1H convert rfc822-to-8bit (ORCPT ); Thu, 3 Oct 2013 04:27:07 -0400 Date: Thu, 3 Oct 2013 11:27:02 +0300 From: Jack Morgenstein To: Alexander Gordeev Cc: linux-kernel@vger.kernel.org, Bjorn Helgaas , Ralf Baechle , Michael Ellerman , Benjamin Herrenschmidt , Martin Schwidefsky , Ingo Molnar , Tejun Heo , Dan Williams , Andy King , Jon Mason , Matt Porter , linux-pci@vger.kernel.org, linux-mips@linux-mips.org, linuxppc-dev@lists.ozlabs.org, linux390@de.ibm.com, linux-s390@vger.kernel.org, x86@kernel.org, linux-ide@vger.kernel.org, iss_storagedev@hp.com, linux-nvme@lists.infradead.org, linux-rdma@vger.kernel.org, netdev@vger.kernel.org, e1000-devel@lists.sourceforge.net, linux-driver@qlogic.com, Solarflare linux maintainers , "VMware, Inc." , linux-scsi@vger.kernel.org, ogerlitz@mellanox.com, eli@mellanox.com Subject: Re: [PATCH RFC 46/77] mlx4: Update MSI/MSI-X interrupts enablement code Message-ID: <20131003112702.6f3210b0@jpm-OptiPlex-GX620> In-Reply-To: References: Organization: Mellanox X-Mailer: Claws Mail 3.8.1 (GTK+ 2.24.17; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2823 Lines: 85 On Wed, 2 Oct 2013 12:49:02 +0200 Alexander Gordeev wrote: UPDATING THIS REPLY. Your change log confused me. The change below is not from a "recent re-design", it is required due to an earlier patch in this patch set. >From the log, I assumed that the change you are talking about is already upstream. I will re-review. -Jack NACK. This change does not do anything logically as far as I can tell. pci_enable_msix in the current upstream kernel itself calls pci_msix_table_size. The current code yields the same resultswill as the code suggested below. (i.e., the suggested code has no effect on optimality). BTW, pci_msix_table_size never returns a value < 0 (if msix is not enabled, it returns 0 for the table size), so the (err < 0) check here is not correct. (I also do not like using "err" here anyway for the value returned by pci_msix_table_size(). There is no error here, and it is simply confusing. -Jack > As result of recent re-design of the MSI/MSI-X interrupts enabling > pattern this driver has to be updated to use the new technique to > obtain a optimal number of MSI/MSI-X interrupts required. > > Signed-off-by: Alexander Gordeev > --- > drivers/net/ethernet/mellanox/mlx4/main.c | 17 ++++++++--------- > 1 files changed, 8 insertions(+), 9 deletions(-) > > diff --git a/drivers/net/ethernet/mellanox/mlx4/main.c > b/drivers/net/ethernet/mellanox/mlx4/main.c index 60c9f4f..377a5ea > 100644 --- a/drivers/net/ethernet/mellanox/mlx4/main.c > +++ b/drivers/net/ethernet/mellanox/mlx4/main.c > @@ -1852,8 +1852,16 @@ static void mlx4_enable_msi_x(struct mlx4_dev > *dev) int i; > > if (msi_x) { > + err = pci_msix_table_size(dev->pdev); > + if (err < 0) > + goto no_msi; > + > + /* Try if at least 2 vectors are available */ > nreq = min_t(int, dev->caps.num_eqs - > dev->caps.reserved_eqs, nreq); > + nreq = min_t(int, nreq, err); > + if (nreq < 2) > + goto no_msi; > > entries = kcalloc(nreq, sizeof *entries, GFP_KERNEL); > if (!entries) > @@ -1862,17 +1870,8 @@ static void mlx4_enable_msi_x(struct mlx4_dev > *dev) for (i = 0; i < nreq; ++i) > entries[i].entry = i; > > - retry: > err = pci_enable_msix(dev->pdev, entries, nreq); > if (err) { > - /* Try again if at least 2 vectors are > available */ > - if (err > 1) { > - mlx4_info(dev, "Requested %d > vectors, " > - "but only %d MSI-X vectors > available, " > - "trying again\n", nreq, > err); > - nreq = err; > - goto retry; > - } > kfree(entries); > goto no_msi; > } -- 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/