netdev - Re: [PATCH] cls_flower: check if filter is in HW before calling fl_hw_destroy

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Date:   Wed, 24 Jan 2018 14:23:17 -0800
From:   Jakub Kicinski <kubakici@...pl>
To:     Sathya Perla <sathya.perla@...adcom.com>
Cc:     netdev@...r.kernel.org, jiri@...nulli.us
Subject: Re: [PATCH] cls_flower: check if filter is in HW before calling
 fl_hw_destroy_filter()

On Wed, 24 Jan 2018 17:12:55 +0530, Sathya Perla wrote:
> When a filter cannot be added in HW (i.e, fl_hw_replace_filter() returns
> error), the TCA_CLS_FLAGS_IN_HW flag is not set in the filter flags.
> 
> This flag (via tc_in_hw()) must be checked before issuing the call
> to delete a filter in HW (fl_hw_destroy_filter()) and before issuing the
> call to query stats (fl_hw_update_stats()).
> 
> Signed-off-by: Sathya Perla <sathya.perla@...adcom.com>

Could you explain why you want to make that change?  Saying "tc_in_hw()
must be checked" is a bit strong, tc_in_hw() is useless from correctness 
POV.  Your patch may be a good optimization, but with shared blocks in
the picture now tc_in_hw() == true doesn't mean it's in *your* HW.