netdev - Re: [net 02/14] Revert "mlx5: move affinity hints assignments to generic code"

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <459db705-4586-9eab-2f5b-15014a6730da@grimberg.me>
Date:   Mon, 25 Dec 2017 15:53:17 +0200
From:   Sagi Grimberg <sagi@...mberg.me>
To:     Saeed Mahameed <saeedm@...lanox.com>,
        "David S. Miller" <davem@...emloft.net>
Cc:     netdev@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>,
        Jes Sorensen <jsorensen@...com>
Subject: Re: [net 02/14] Revert "mlx5: move affinity hints assignments to
 generic code"


> Before the offending commit, mlx5 core did the IRQ affinity itself,
> and it seems that the new generic code have some drawbacks and one
> of them is the lack for user ability to modify irq affinity after
> the initial affinity values got assigned.
> 
> The issue is still being discussed and a solution in the new generic code
> is required, until then we need to revert this patch.
> 
> This fixes the following issue:
> echo <new affinity> > /proc/irq/<x>/smp_affinity
> fails with  -EIO
> 
> This reverts commit a435393acafbf0ecff4deb3e3cb554b34f0d0664.
> Note: kept mlx5_get_vector_affinity in include/linux/mlx5/driver.h since
 > it is used in mlx5_ib driver.

This won't work for sure because the msi_desc affinity cpumask won't
ever be populated. You need to re-implement it in mlx5 if you don't want
to break rdma ULPs that rely on it.