From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E0895C433B4 for ; Mon, 12 Apr 2021 17:34:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B3B1461261 for ; Mon, 12 Apr 2021 17:34:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239731AbhDLRe7 (ORCPT ); Mon, 12 Apr 2021 13:34:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:44206 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239298AbhDLRe7 (ORCPT ); Mon, 12 Apr 2021 13:34:59 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 621F36121F; Mon, 12 Apr 2021 17:34:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1618248881; bh=X4vHobQGMf5yS8EZZFI9B97njb3wMr6W5r0ESrF0RH4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QtBQiOzzR77bG1BUDCJ4H8wTpZ0H3J0MsrXln+iKYvnInaHFSc/l0LOWlH8Nz3au7 aRgTlT4yELRjmT0yqg89hzed+F+Yy8qtjZdEqSVenwze6Gi9tOzQbUIhg2Ni7ZtvPR T1N5RVX34qsFsVXDB9dfZ+vBMYTeTdpg5WRc2RYwB/j7daaxCVgX8yHwqHcz92Zmer CmrPc3zmG3BpXFCusL0uNiSUzoyDd7OjUk12eZC00KwXW40YEfjJ00IFGVdmiqx8u6 dxBkZMjYGs+xc/Sf64zxt/ifU3iOXj7SxNowK9JQZ+9OTkUvNEOLoZI4Sj1wpw+yav bNkqlcEsIGuWQ== Date: Mon, 12 Apr 2021 20:34:37 +0300 From: Leon Romanovsky To: Gioh Kim Cc: Jinpu Wang , linux-rdma , Bart Van Assche , Doug Ledford , Jason Gunthorpe , Haris Iqbal , Gioh Kim Subject: Re: [PATCHv2 for-next 1/3] RDMA/rtrs-clt: Print more info when an error happens Message-ID: References: <20210406123639.202899-1-gi-oh.kim@ionos.com> <20210406123639.202899-2-gi-oh.kim@ionos.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On Mon, Apr 12, 2021 at 04:00:55PM +0200, Gioh Kim wrote: > On Mon, Apr 12, 2021 at 2:54 PM Jinpu Wang wrote: > > > > On Mon, Apr 12, 2021 at 2:41 PM Leon Romanovsky wrote: > > > > > > On Mon, Apr 12, 2021 at 02:22:51PM +0200, Jinpu Wang wrote: > > > > On Tue, Apr 6, 2021 at 2:41 PM Leon Romanovsky wrote: > > > > > > > > > > On Tue, Apr 06, 2021 at 02:36:37PM +0200, Gioh Kim wrote: > > > > > > From: Gioh Kim > > > > > > > > > > > > Client prints only error value and it is not enough for debugging. > > > > > > > > > > > > 1. When client receives an error from server: > > > > > > the client does not only print the error value but also > > > > > > more information of server connection. > > > > > > > > > > > > 2. When client failes to send IO: > > > > > > the client gets an error from RDMA layer. It also > > > > > > print more information of server connection. > > > > > > > > > > > > Signed-off-by: Gioh Kim > > > > > > Signed-off-by: Jack Wang > > > > > > --- > > > > > > drivers/infiniband/ulp/rtrs/rtrs-clt.c | 33 ++++++++++++++++++++++---- > > > > > > 1 file changed, 29 insertions(+), 4 deletions(-) > > > > > > > > > > > > diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.c b/drivers/infiniband/ulp/rtrs/rtrs-clt.c > > > > > > index 5062328ac577..a534b2b09e13 100644 > > > > > > --- a/drivers/infiniband/ulp/rtrs/rtrs-clt.c > > > > > > +++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.c > > > > > > @@ -437,6 +437,11 @@ static void complete_rdma_req(struct rtrs_clt_io_req *req, int errno, > > > > > > req->in_use = false; > > > > > > req->con = NULL; > > > > > > > > > > > > + if (unlikely(errno)) { > > > > > > > > > > I'm sorry, but all your patches are full of these likely/unlikely cargo > > > > > cult. Can you please provide supportive performance data or delete all > > > > > likely/unlikely in all rtrs code? > > > > > > > > Hi Leon, > > > > > > > > All the likely/unlikely from the non-fast path was removed as you > > > > suggested in the past. > > > > This one is on IO path, my understanding is for the fast path, with > > > > likely/unlikely macro, > > > > the compiler will optimize the code for better branch prediction. > > > > > > In theory yes, in practice. gcc 10 generated same assembly code when I > > > placed likely() and replaced it with unlikely() later. > > Even-thought gcc 10 generated the same assembly code, > there is no guarantee for gcc 11 or gcc 12. > > I am reviewing rtrs source file and have found some unnecessary likely/unlikely. > But I think likely/unlikely are necessary for extreme cases. > I will have a discussion with my colleagues and inform you of the result. Please come with performance data. Thanks