Messages in this thread Patch in this message | | | From | Salil Mehta <> | Subject | RE: [Intel-wired-lan] [PATCH V2 net] ice: Re-organizes reqstd/avail {R, T}XQ check/code for efficiency+readability | Date | Wed, 21 Apr 2021 07:41:13 +0000 |
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> From: Paul Menzel [mailto:pmenzel@molgen.mpg.de] > Sent: Wednesday, April 21, 2021 6:36 AM > To: Salil Mehta <salil.mehta@huawei.com> > Cc: linuxarm@openeuler.org; netdev@vger.kernel.org; Linuxarm > <linuxarm@huawei.com>; linux-kernel@vger.kernel.org; Jeff Kirsher > <jeffrey.t.kirsher@intel.com>; intel-wired-lan@lists.osuosl.org; David S. > Miller <davem@davemloft.net>; Jakub Kicinski <kuba@kernel.org> > Subject: Re: [Intel-wired-lan] [PATCH V2 net] ice: Re-organizes reqstd/avail > {R, T}XQ check/code for efficiency+readability > > Dear Salil, > > > Thank you very much for your patch.
Thanks for the review.
> In the git commit message summary, could you please use imperative mood [1]?
No issues. There is always a scope of improvement.
> > Re-organize reqstd/avail {R, T}XQ check/code for efficiency+readability > > It’s a bit long though. Maybe: > > Avoid unnecessary assignment with user specified {R,T}XQs
Umm..above conveys the wrong meaning as this is not what patch is doing.
If you see the code, in the presence of the user specified {R,T}XQs it avoids fetching available {R,T}XQ count.
What about below?
"Avoid unnecessary avail_{r,t}xq assignments if user has specified Qs"
> Am 14.04.21 um 00:44 schrieb Salil Mehta: > > If user has explicitly requested the number of {R,T}XQs, then it is > > unnecessary to get the count of already available {R,T}XQs from the > > PF avail_{r,t}xqs bitmap. This value will get overridden by user specified > > value in any case. > > > > This patch does minor re-organization of the code for improving the flow > > and readabiltiy. This scope of improvement was found during the review of > > readabil*it*y
Thanks. Missed that earlier. My shaky fingers :(
> > the ICE driver code. > > > > FYI, I could not test this change due to unavailability of the hardware. > > It would be helpful if somebody can test this patch and provide Tested-by > > Tag. Many thanks! > > This should go outside the commit message (below the --- for example).
Agreed.
> > Fixes: 87324e747fde ("ice: Implement ethtool ops for channels") > > Did you check the behavior before is actually a bug? Or is it just for > the detection heuristic for commits to be applied to the stable series?
Right, later was the idea.
> > Cc: intel-wired-lan@lists.osuosl.org > > Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com> > > Signed-off-by: Salil Mehta <salil.mehta@huawei.com> > > -- > > Change V1->V2 > > (*) Fixed the comments from Anthony Nguyen(Intel) > > Link: https://lkml.org/lkml/2021/4/12/1997 > > --- > > drivers/net/ethernet/intel/ice/ice_lib.c | 14 ++++++++------ > > 1 file changed, 8 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/net/ethernet/intel/ice/ice_lib.c > b/drivers/net/ethernet/intel/ice/ice_lib.c > > index d13c7fc8fb0a..d77133d6baa7 100644 > > --- a/drivers/net/ethernet/intel/ice/ice_lib.c > > +++ b/drivers/net/ethernet/intel/ice/ice_lib.c > > @@ -161,12 +161,13 @@ static void ice_vsi_set_num_qs(struct ice_vsi *vsi, u16 > vf_id) > > > > switch (vsi->type) { > > case ICE_VSI_PF: > > - vsi->alloc_txq = min3(pf->num_lan_msix, > > - ice_get_avail_txq_count(pf), > > - (u16)num_online_cpus()); > > if (vsi->req_txq) { > > vsi->alloc_txq = vsi->req_txq; > > vsi->num_txq = vsi->req_txq; > > + } else { > > + vsi->alloc_txq = min3(pf->num_lan_msix, > > + ice_get_avail_txq_count(pf), > > + (u16)num_online_cpus()); > > } > > I am curious, did you check the compiler actually creates different > code, or did it notice the inefficiency by itself and optimized it already?
I have not looked into that detail but irrespective of what compiler generates I would like to keep the code in a shape which is more efficient and more readable.
I do understand in certain cases we have to do tradeoff between efficiency and readability but I do not see that here.
> > pf->num_lan_tx = vsi->alloc_txq; > > @@ -175,12 +176,13 @@ static void ice_vsi_set_num_qs(struct ice_vsi *vsi, u16 > vf_id) > > if (!test_bit(ICE_FLAG_RSS_ENA, pf->flags)) { > > vsi->alloc_rxq = 1; > > } else { > > - vsi->alloc_rxq = min3(pf->num_lan_msix, > > - ice_get_avail_rxq_count(pf), > > - (u16)num_online_cpus()); > > if (vsi->req_rxq) { > > vsi->alloc_rxq = vsi->req_rxq; > > vsi->num_rxq = vsi->req_rxq; > > + } else { > > + vsi->alloc_rxq = min3(pf->num_lan_msix, > > + ice_get_avail_rxq_count(pf), > > + (u16)num_online_cpus()); > > } > > } > > > > > Kind regards, > > Paul
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