[ovs-dev] [PATCH] INSTALL: Note about compiler atomics support.

Jarno Rajahalme jrajahalme at nicira.com
Wed Jun 4 16:38:09 UTC 2014


Pushed, thanks.

  Jarno

On Jun 3, 2014, at 11:38 PM, YAMAMOTO Takashi <yamamoto at valinux.co.jp> wrote:

>> OVS is slow when compiled with pthreads atomics.  Add a generic note
>> in INSTALL, with a reference to lib/ovs-atomic.h, where a new comment
>> provides additional detail.
>> 
>> Signed-off-by: Jarno Rajahalme <jrajahalme at nicira.com>
> 
> Acked-by: YAMAMOTO Takashi <yamamoto at valinux.co.jp>
> 
>> ---
>> INSTALL          |    4 ++++
>> lib/ovs-atomic.h |    3 +++
>> 2 files changed, 7 insertions(+)
>> 
>> diff --git a/INSTALL b/INSTALL
>> index 5c869b2..7b08172 100644
>> --- a/INSTALL
>> +++ b/INSTALL
>> @@ -28,6 +28,10 @@ you will need the following software:
>>           analysis and thread-safety checks.  For Ubuntu, there are
>>           nightly built packages available on clang's website.
>> 
>> +        * While OVS may be compatible with other compilers, optimal
>> +          support for atomic operations may be missing, making OVS
>> +          very slow (see lib/ovs-atomic.h).
>> +
>>     - libssl, from OpenSSL, is optional but recommended if you plan to
>>       connect the Open vSwitch to an OpenFlow controller.  libssl is
>>       required to establish confidentiality and authenticity in the
>> diff --git a/lib/ovs-atomic.h b/lib/ovs-atomic.h
>> index c21b7ee..2452846 100644
>> --- a/lib/ovs-atomic.h
>> +++ b/lib/ovs-atomic.h
>> @@ -257,6 +257,9 @@
>>     #elif HAVE_GCC4_ATOMICS
>>         #include "ovs-atomic-gcc4+.h"
>>     #else
>> +        /* ovs-atomic-pthreads implementation is provided for portability.
>> +         * It might be too slow for real use because Open vSwitch is
>> +         * optimized for platforms where real atomic ops are available. */
>>         #include "ovs-atomic-pthreads.h"
>>     #endif
>> #undef IN_OVS_ATOMIC_H
>> -- 
>> 1.7.10.4
>> 
>> _______________________________________________
>> dev mailing list
>> dev at openvswitch.org
>> http://openvswitch.org/mailman/listinfo/dev

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.openvswitch.org/pipermail/ovs-dev/attachments/20140604/83988db9/attachment-0005.html>


More information about the dev mailing list