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 for Android: free password hash cracker in your pocket
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Mon, 6 Mar 2017 18:27:52 +0530
From:   Sunil Kovvuri <>
To:     Robin Murphy <>
Cc:     David Miller <>,
        Linux Netdev List <>,
        Sunil Goutham <>,
        LKML <>,
        LAKML <>
Subject: Re: [PATCH 1/4] net: thunderx: Fix IOMMU translation faults

>> We are seeing a 0.75Mpps drop with IP forwarding rate due to that.
>> Hence I have restricted calling DMA interfaces to only when IOMMU is enabled.
> What's 0.07Mpps as a percentage of baseline? On a correctly configured
> coherent arm64 system, in the absence of an IOMMU, dma_map_*() is
> essentially just virt_to_phys() behind a function call or two, so I'd be
> interested to know where any non-trivial overhead might be coming from.

It's a 5% drop and yes device is configured as coherent.
And the drop is due to additional function calls.


Powered by blists - more mailing lists