From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Horman Subject: Re: [PATCH 3/5] testpmd: Change rxfreet default to 32 Date: Wed, 17 Sep 2014 11:29:45 -0400 Message-ID: <20140917152945.GF4213@localhost.localdomain> References: <1410948102-12740-1-git-send-email-bruce.richardson@intel.com> <1410948102-12740-4-git-send-email-bruce.richardson@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: dev-VfR2kkLFssw@public.gmane.org To: Bruce Richardson Return-path: Content-Disposition: inline In-Reply-To: <1410948102-12740-4-git-send-email-bruce.richardson-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces-VfR2kkLFssw@public.gmane.org Sender: "dev" On Wed, Sep 17, 2014 at 11:01:40AM +0100, Bruce Richardson wrote: > To improve performance by using bulk alloc or vectored RX routines, we > need to set rx free threshold (rxfreet) value to 32, so make this the > testpmd default. > > Signed-off-by: Bruce Richardson > --- > app/test-pmd/testpmd.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c > index 9f6cdc4..5751607 100644 > --- a/app/test-pmd/testpmd.c > +++ b/app/test-pmd/testpmd.c > @@ -225,7 +225,7 @@ struct rte_eth_thresh tx_thresh = { > /* > * Configurable value of RX free threshold. > */ > -uint16_t rx_free_thresh = 0; /* Immediately free RX descriptors by default. */ > +uint16_t rx_free_thresh = 32; /* Refill RX descriptors once every 32 packets */ > Why 32? Was that an experimentally determined value? Does it hold true for all PMD's?