From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl1-f193.google.com (mail-pl1-f193.google.com [209.85.214.193]) by dpdk.org (Postfix) with ESMTP id 7DB011B295 for ; Mon, 15 Apr 2019 17:38:39 +0200 (CEST) Received: by mail-pl1-f193.google.com with SMTP id w24so8755146plp.2 for ; Mon, 15 Apr 2019 08:38:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=eOB3zvTl3RZqAGn8IKyszbjDfxFFg+SYuuYaypH1yIQ=; b=XxYu7JlC3Eh2Q6wW90siDUn3EeGEN9JobtRCORjujKCRhhWtKjlHqqz1GgwLiTohQf nwxKPtS8udwdqb/FnaPORCvKZPj4XwUDdWN+G13eQZGtetPPYLIZ6GH/SPJ8tra5gIMV wrnV9WlJKj3QhC481WprEys/0H0ijS0UzBvAiqqsiVvceJdDrkUXqC96OI915xfxXhRZ Pe47Ps6KVYWJ29MgjVN4miisoXzkfH02gvja2pjGEjjUWakhdrJ3H+huOK6wYTCR5r9f NcJ2kVfW4Ac3nNvG/dz/UtAmaKiBxxEQgegGNyRdtfthI/1umtLgtE1KumNnaLt8drTq 0XKQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=eOB3zvTl3RZqAGn8IKyszbjDfxFFg+SYuuYaypH1yIQ=; b=twl0kyOf1i7AaNjgba+tuTKfKl34zdngLkk7WbzMs9N4a0nltrfLF3AFP/WbuZOecw VfF/XO4dqldvtmXpJv9+gsY3JoL4hs/YWZRy/TafJoo/s3smRj+9KKGrBvTbXatm6/eL AgV5FS4R352ueJEcjj4hnrapPLpwNTWxGSuxOJ/C7bqk/e+CMZyQEiwIP0fr+/DtDM10 KoYXFmjcnJfIQAU+0BkZz5HeSaWTVM9YHJsbTadXIpPOSumtRktZD9xxhz5638KTDBEx sEyoN1HtX1hAoSS83/DcTKBUYmwe+TSxoSQ7EFeU4LMjkWPNYKUBX2IMxLa3/8+5pZUg NM2w== X-Gm-Message-State: APjAAAU34HpZck30uD4viGYt+zu2LwUv82N9FQ9SsvHIxYpcEP8fg1ge sbpuBT4TWZpn8Z4HETLfcZX4QA== X-Google-Smtp-Source: APXvYqx4HkEqd3V8/EwQX7hNoqMQUtb9oN+aZK5fbPO88QRGmws+VYsCU9TYdtu+1/9w5+o0vJGoyg== X-Received: by 2002:a17:902:e101:: with SMTP id cc1mr76797658plb.129.1555342718103; Mon, 15 Apr 2019 08:38:38 -0700 (PDT) Received: from shemminger-XPS-13-9360 (204-195-22-127.wavecable.com. [204.195.22.127]) by smtp.gmail.com with ESMTPSA id z8sm61913492pgz.3.2019.04.15.08.38.37 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 15 Apr 2019 08:38:37 -0700 (PDT) Date: Mon, 15 Apr 2019 08:38:34 -0700 From: Stephen Hemminger To: "Ananyev, Konstantin" Cc: Honnappa Nagarahalli , "paulmck@linux.ibm.com" , "Kovacevic, Marko" , "dev@dpdk.org" , "Gavin Hu (Arm Technology China)" , Dharmik Thakkar , Malvika Gupta , nd Message-ID: <20190415083834.31b38ed3@shemminger-XPS-13-9360> In-Reply-To: <2601191342CEEE43887BDE71AB9772580148A97E53@irsmsx105.ger.corp.intel.com> References: <20181122033055.3431-1-honnappa.nagarahalli@arm.com> <20190412202039.46902-1-honnappa.nagarahalli@arm.com> <20190412202039.46902-2-honnappa.nagarahalli@arm.com> <20190412150650.3709358e@shemminger-XPS-13-9360> <20190412160629.670eacd1@shemminger-XPS-13-9360> <2601191342CEEE43887BDE71AB9772580148A97E53@irsmsx105.ger.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH v5 1/3] rcu: add RCU library supporting QSBR mechanism X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 15 Apr 2019 15:38:39 -0000 On Mon, 15 Apr 2019 12:24:47 +0000 "Ananyev, Konstantin" wrote: > > -----Original Message----- > > From: Stephen Hemminger [mailto:stephen@networkplumber.org] > > Sent: Saturday, April 13, 2019 12:06 AM > > To: Honnappa Nagarahalli > > Cc: Ananyev, Konstantin ; paulmck@linux.ibm.com; Kovacevic, Marko ; > > dev@dpdk.org; Gavin Hu (Arm Technology China) ; Dharmik Thakkar ; Malvika Gupta > > ; nd > > Subject: Re: [PATCH v5 1/3] rcu: add RCU library supporting QSBR mechanism > > > > On Fri, 12 Apr 2019 22:24:45 +0000 > > Honnappa Nagarahalli wrote: > > > > > > > > > > On Fri, 12 Apr 2019 15:20:37 -0500 > > > > Honnappa Nagarahalli wrote: > > > > > > > > > Add RCU library supporting quiescent state based memory reclamation > > > > method. > > > > > This library helps identify the quiescent state of the reader threads > > > > > so that the writers can free the memory associated with the lock less > > > > > data structures. > > > > > > > > > > Signed-off-by: Honnappa Nagarahalli > > > > > Reviewed-by: Steve Capper > > > > > Reviewed-by: Gavin Hu > > > > > Reviewed-by: Ola Liljedahl > > > > > Acked-by: Konstantin Ananyev > > > > > > > > After evaluating long term API/ABI issues, I think you need to get rid of almost > > > > all use of inline and visible structures. Yes it might be marginally slower, but > > > > you thank me the first time you have to fix something. > > > > > > > Agree, I was planning on another version to address this (I am yet to take a look at your patch addressing the ABI). > > > The structure visibility definitely needs to be addressed. > > > For the inline functions, is the plan to convert all the inline functions in DPDK? If yes, I think we need to consider the performance > > difference. May be consider L3-fwd application, change all the inline functions in its path and run a test? > > > > Every function that is not in the direct datapath should not be inline. > > Exceptions or things like rx/tx burst, ring enqueue/dequeue, and packet alloc/free > > Plus synchronization routines: spin/rwlock/barrier, etc. > I think rcu should be one of such exceptions - it is just another synchronization mechanism after all > (just a bit more sophisticated). > Konstantin If you look at the other userspace RCU, you wil see that the only inlines are the rcu_read_lock,rcu_read_unlock and rcu_reference/rcu_assign_pointer. The synchronization logic is all real functions. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by dpdk.space (Postfix) with ESMTP id 241CEA00E6 for ; Mon, 15 Apr 2019 17:38:42 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id AE7671B296; Mon, 15 Apr 2019 17:38:40 +0200 (CEST) Received: from mail-pl1-f193.google.com (mail-pl1-f193.google.com [209.85.214.193]) by dpdk.org (Postfix) with ESMTP id 7DB011B295 for ; Mon, 15 Apr 2019 17:38:39 +0200 (CEST) Received: by mail-pl1-f193.google.com with SMTP id w24so8755146plp.2 for ; Mon, 15 Apr 2019 08:38:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=eOB3zvTl3RZqAGn8IKyszbjDfxFFg+SYuuYaypH1yIQ=; b=XxYu7JlC3Eh2Q6wW90siDUn3EeGEN9JobtRCORjujKCRhhWtKjlHqqz1GgwLiTohQf nwxKPtS8udwdqb/FnaPORCvKZPj4XwUDdWN+G13eQZGtetPPYLIZ6GH/SPJ8tra5gIMV wrnV9WlJKj3QhC481WprEys/0H0ijS0UzBvAiqqsiVvceJdDrkUXqC96OI915xfxXhRZ Pe47Ps6KVYWJ29MgjVN4miisoXzkfH02gvja2pjGEjjUWakhdrJ3H+huOK6wYTCR5r9f NcJ2kVfW4Ac3nNvG/dz/UtAmaKiBxxEQgegGNyRdtfthI/1umtLgtE1KumNnaLt8drTq 0XKQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=eOB3zvTl3RZqAGn8IKyszbjDfxFFg+SYuuYaypH1yIQ=; b=twl0kyOf1i7AaNjgba+tuTKfKl34zdngLkk7WbzMs9N4a0nltrfLF3AFP/WbuZOecw VfF/XO4dqldvtmXpJv9+gsY3JoL4hs/YWZRy/TafJoo/s3smRj+9KKGrBvTbXatm6/eL AgV5FS4R352ueJEcjj4hnrapPLpwNTWxGSuxOJ/C7bqk/e+CMZyQEiwIP0fr+/DtDM10 KoYXFmjcnJfIQAU+0BkZz5HeSaWTVM9YHJsbTadXIpPOSumtRktZD9xxhz5638KTDBEx sEyoN1HtX1hAoSS83/DcTKBUYmwe+TSxoSQ7EFeU4LMjkWPNYKUBX2IMxLa3/8+5pZUg NM2w== X-Gm-Message-State: APjAAAU34HpZck30uD4viGYt+zu2LwUv82N9FQ9SsvHIxYpcEP8fg1ge sbpuBT4TWZpn8Z4HETLfcZX4QA== X-Google-Smtp-Source: APXvYqx4HkEqd3V8/EwQX7hNoqMQUtb9oN+aZK5fbPO88QRGmws+VYsCU9TYdtu+1/9w5+o0vJGoyg== X-Received: by 2002:a17:902:e101:: with SMTP id cc1mr76797658plb.129.1555342718103; Mon, 15 Apr 2019 08:38:38 -0700 (PDT) Received: from shemminger-XPS-13-9360 (204-195-22-127.wavecable.com. [204.195.22.127]) by smtp.gmail.com with ESMTPSA id z8sm61913492pgz.3.2019.04.15.08.38.37 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 15 Apr 2019 08:38:37 -0700 (PDT) Date: Mon, 15 Apr 2019 08:38:34 -0700 From: Stephen Hemminger To: "Ananyev, Konstantin" Cc: Honnappa Nagarahalli , "paulmck@linux.ibm.com" , "Kovacevic, Marko" , "dev@dpdk.org" , "Gavin Hu (Arm Technology China)" , Dharmik Thakkar , Malvika Gupta , nd Message-ID: <20190415083834.31b38ed3@shemminger-XPS-13-9360> In-Reply-To: <2601191342CEEE43887BDE71AB9772580148A97E53@irsmsx105.ger.corp.intel.com> References: <20181122033055.3431-1-honnappa.nagarahalli@arm.com> <20190412202039.46902-1-honnappa.nagarahalli@arm.com> <20190412202039.46902-2-honnappa.nagarahalli@arm.com> <20190412150650.3709358e@shemminger-XPS-13-9360> <20190412160629.670eacd1@shemminger-XPS-13-9360> <2601191342CEEE43887BDE71AB9772580148A97E53@irsmsx105.ger.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH v5 1/3] rcu: add RCU library supporting QSBR mechanism X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Message-ID: <20190415153834.0RH0lGBIEMU3VOKmwSNE1rggERVPzVPchR1yhEMtZgQ@z> On Mon, 15 Apr 2019 12:24:47 +0000 "Ananyev, Konstantin" wrote: > > -----Original Message----- > > From: Stephen Hemminger [mailto:stephen@networkplumber.org] > > Sent: Saturday, April 13, 2019 12:06 AM > > To: Honnappa Nagarahalli > > Cc: Ananyev, Konstantin ; paulmck@linux.ibm.com; Kovacevic, Marko ; > > dev@dpdk.org; Gavin Hu (Arm Technology China) ; Dharmik Thakkar ; Malvika Gupta > > ; nd > > Subject: Re: [PATCH v5 1/3] rcu: add RCU library supporting QSBR mechanism > > > > On Fri, 12 Apr 2019 22:24:45 +0000 > > Honnappa Nagarahalli wrote: > > > > > > > > > > On Fri, 12 Apr 2019 15:20:37 -0500 > > > > Honnappa Nagarahalli wrote: > > > > > > > > > Add RCU library supporting quiescent state based memory reclamation > > > > method. > > > > > This library helps identify the quiescent state of the reader threads > > > > > so that the writers can free the memory associated with the lock less > > > > > data structures. > > > > > > > > > > Signed-off-by: Honnappa Nagarahalli > > > > > Reviewed-by: Steve Capper > > > > > Reviewed-by: Gavin Hu > > > > > Reviewed-by: Ola Liljedahl > > > > > Acked-by: Konstantin Ananyev > > > > > > > > After evaluating long term API/ABI issues, I think you need to get rid of almost > > > > all use of inline and visible structures. Yes it might be marginally slower, but > > > > you thank me the first time you have to fix something. > > > > > > > Agree, I was planning on another version to address this (I am yet to take a look at your patch addressing the ABI). > > > The structure visibility definitely needs to be addressed. > > > For the inline functions, is the plan to convert all the inline functions in DPDK? If yes, I think we need to consider the performance > > difference. May be consider L3-fwd application, change all the inline functions in its path and run a test? > > > > Every function that is not in the direct datapath should not be inline. > > Exceptions or things like rx/tx burst, ring enqueue/dequeue, and packet alloc/free > > Plus synchronization routines: spin/rwlock/barrier, etc. > I think rcu should be one of such exceptions - it is just another synchronization mechanism after all > (just a bit more sophisticated). > Konstantin If you look at the other userspace RCU, you wil see that the only inlines are the rcu_read_lock,rcu_read_unlock and rcu_reference/rcu_assign_pointer. The synchronization logic is all real functions.