Re: [Gems-users] CONFIG_FETCH_THREADS_PER_CYCLE parameter in GEMS2.1


Date: Wed, 10 Sep 2008 17:39:56 -0500 (CDT)
From: Luke Yen <lyen@xxxxxxxxxxx>
Subject: Re: [Gems-users] CONFIG_FETCH_THREADS_PER_CYCLE parameter in GEMS2.1

Yes, it looks like the condition guarding the update to num_threads_fetched is too strict:

if(num_fetched[proc] != 0 && m_fetch_status[proc] != PSEQ_FETCH_ITLBMISS){

   should probably be:

   if(num_fetched[proc] != 0){

  I'll make a note of this bug for a future update.

   Luke


On Wed, 10 Sep 2008, Daniel Sánchez Pedreño wrote:

Dear list, as I've seen in config/config.defaults,
CONFIG_FETCH_THREADS_PER_CYCLE  "*specifies how many threads to fetch from
in each cycle*". However, I've seen that instructions from different threads
can be fetched in the same cycle. This situation happens  when a thread
fetches some instructions normally but the final one is not because of a
cache or itlb miss. The problem is that altough this thread has fetched
normally several instructions *num_thread_fetched* is not incremented so
another thread is able to fetch.

I think this behaviour is not correct if we have set
CONFIG_FETCH_THREADS_PER_CYCLE to 1, but I would like a confirmation.
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