netdev - Re: [PATCH net 1/4] net: aquantia: tx clean budget logic error

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Message-Id: <20190526.221556.885075788672387642.davem@davemloft.net>
Date:   Sun, 26 May 2019 22:15:56 -0700 (PDT)
From:   David Miller <davem@...emloft.net>
To:     Igor.Russkikh@...antia.com
Cc:     netdev@...r.kernel.org
Subject: Re: [PATCH net 1/4] net: aquantia: tx clean budget logic error

From: Igor Russkikh <Igor.Russkikh@...antia.com>
Date: Sat, 25 May 2019 09:57:59 +0000

> In case no other traffic happening on the ring, full tx cleanup
> may not be completed. That may cause socket buffer to overflow
> and tx traffic to stuck until next activity on the ring happens.
> 
> This is due to logic error in budget variable decrementor.
> Variable is compared with zero, and then post decremented,
> causing it to become MAX_INT. Solution is remove decrementor
> from the `for` statement and rewrite it in a clear way.
> 
> Fixes: b647d3980948e ("net: aquantia: Add tx clean budget and valid budget handling logic")
> Signed-off-by: Igor Russkikh <igor.russkikh@...antia.com>

I think the TX clean budget is a very bad idea.

You should always do as much TX clean work as there is TODO.