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From: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
To: Bjorn Helgaas <helgaas@kernel.org>,
	Ganesh Goudar <ganeshgr@chelsio.com>,
	Michael Chan <michael.chan@broadcom.com>,
	Ariel Elior <ariel.elior@cavium.com>
Cc: linux-pci@vger.kernel.org, everest-linux-l2@cavium.com,
	intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org, Tal Gilboa <talgi@mellanox.com>,
	Tariq Toukan <tariqt@mellanox.com>,
	Jacob Keller <jacob.e.keller@intel.com>,
	Jakub Kicinski <kubakici@wp.pl>
Subject: Re: [PATCH v6 5/5] PCI: Remove unused pcie_get_minimum_link()
Date: Thu, 10 May 2018 13:34:47 -0700	[thread overview]
Message-ID: <ea4c716024a30ed834b1121adb8c2cb1deff2c97.camel@intel.com> (raw)
In-Reply-To: <20180510163357.GB190385@bhelgaas-glaptop.roam.corp.google.com>

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On Thu, 2018-05-10 at 11:33 -0500, Bjorn Helgaas wrote:
> On Thu, May 03, 2018 at 03:00:43PM -0500, Bjorn Helgaas wrote:
> > From: Bjorn Helgaas <bhelgaas@google.com>
> > 
> > In some cases pcie_get_minimum_link() returned misleading
> > information
> > because it found the slowest link and the narrowest link without
> > considering the total bandwidth of the link.
> > 
> > For example, consider a path with these two links:
> > 
> >    - 16.0 GT/s  x1 link  (16.0 * 10^9 * 128 / 130) *  1 / 8 = 1969
> > MB/s
> >    -  2.5 GT/s x16 link  ( 2.5 * 10^9 *   8 /  10) * 16 / 8 = 4000
> > MB/s
> > 
> > The available bandwidth of the path is limited by the 16 GT/s link
> > to about
> > 1969 MB/s, but pcie_get_minimum_link() returned 2.5 GT/s x1, which
> > corresponds to only 250 MB/s.
> > 
> > Callers should use pcie_print_link_status() instead, or
> > pcie_bandwidth_available() if they need more detailed information.
> > 
> > Remove pcie_get_minimum_link() since there are no callers left.
> > 
> > Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
> 
> Hi Jeff,
> 
> I got your note that you applied this to dev-queue.  I assume that
> means you also applied the preceding patches that removed all the
> users.  I got a note about ixgbe, but not the others, so I'm just
> double-checking.

I did initially apply it, but realized that I would have to apply the
earlier patches as well, which did not pertain to the Intel wired LAN
drivers.  So I have removed this patch from queue and will only be
testing the ixgbe patch of the series, which Andrew has already tested
and responded to.

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  reply	other threads:[~2018-05-10 20:33 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-03 20:00 [PATCH v6 0/5] PCI: Improve PCIe link status reporting Bjorn Helgaas
2018-05-03 20:00 ` [PATCH v6 1/5] bnx2x: Report PCIe link properties with pcie_print_link_status() Bjorn Helgaas
2018-05-03 20:00 ` [PATCH v6 2/5] bnxt_en: " Bjorn Helgaas
2018-05-03 20:00 ` [PATCH v6 3/5] cxgb4: " Bjorn Helgaas
2018-05-03 20:00 ` [PATCH v6 4/5] ixgbe: " Bjorn Helgaas
2018-05-10 20:37   ` Jeff Kirsher
2018-05-03 20:00 ` [PATCH v6 5/5] PCI: Remove unused pcie_get_minimum_link() Bjorn Helgaas
2018-05-10 16:33   ` Bjorn Helgaas
2018-05-10 20:34     ` Jeff Kirsher [this message]
2018-05-03 20:29 ` [PATCH v6 0/5] PCI: Improve PCIe link status reporting Keller, Jacob E
2018-05-10 22:29 ` Bjorn Helgaas
2018-05-23 21:46 ` Bjorn Helgaas
2018-05-24 10:18   ` Ganesh Goudar

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