From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.droids-corp.org (zoll.droids-corp.org [94.23.50.67]) by dpdk.org (Postfix) with ESMTP id 8C8875960 for ; Sun, 8 Feb 2015 21:00:55 +0100 (CET) Received: from was59-1-82-226-113-214.fbx.proxad.net ([82.226.113.214] helo=[192.168.0.10]) by mail.droids-corp.org with esmtpsa (TLS1.2:DHE_RSA_AES_128_CBC_SHA1:128) (Exim 4.80) (envelope-from ) id 1YKY5r-0005Pm-0D; Sun, 08 Feb 2015 21:04:42 +0100 Message-ID: <54D7C069.4020900@6wind.com> Date: Sun, 08 Feb 2015 21:00:41 +0100 From: Olivier MATZ User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.3.0 MIME-Version: 1.0 To: Cunming Liang , dev@dpdk.org References: <1422491072-5114-1-git-send-email-cunming.liang@intel.com> <1422842559-13617-1-git-send-email-cunming.liang@intel.com> <1422842559-13617-9-git-send-email-cunming.liang@intel.com> In-Reply-To: <1422842559-13617-9-git-send-email-cunming.liang@intel.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH v4 08/17] eal: apply affinity of EAL thread by assigned cpuset X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 08 Feb 2015 20:00:55 -0000 Hi, On 02/02/2015 03:02 AM, Cunming Liang wrote: > EAL threads use assigned cpuset to set core affinity during startup. > It keeps 1:1 mapping, if no '--lcores' option is used. > > [...] > > lib/librte_eal/bsdapp/eal/eal.c | 13 ++++--- > lib/librte_eal/bsdapp/eal/eal_thread.c | 63 +++++++++--------------------- > lib/librte_eal/linuxapp/eal/eal.c | 7 +++- > lib/librte_eal/linuxapp/eal/eal_thread.c | 67 +++++++++++--------------------- > 4 files changed, 54 insertions(+), 96 deletions(-) > > diff --git a/lib/librte_eal/bsdapp/eal/eal.c b/lib/librte_eal/bsdapp/eal/eal.c > index 69f3c03..98c5a83 100644 > --- a/lib/librte_eal/bsdapp/eal/eal.c > +++ b/lib/librte_eal/bsdapp/eal/eal.c > @@ -432,6 +432,7 @@ rte_eal_init(int argc, char **argv) > int i, fctret, ret; > pthread_t thread_id; > static rte_atomic32_t run_once = RTE_ATOMIC32_INIT(0); > + char cpuset[CPU_STR_LEN]; > > if (!rte_atomic32_test_and_set(&run_once)) > return -1; > @@ -502,13 +503,17 @@ rte_eal_init(int argc, char **argv) > if (rte_eal_pci_init() < 0) > rte_panic("Cannot init PCI\n"); > > - RTE_LOG(DEBUG, EAL, "Master core %u is ready (tid=%p)\n", > - rte_config.master_lcore, thread_id); > - > eal_check_mem_on_local_socket(); > > rte_eal_mcfg_complete(); > > + eal_thread_init_master(rte_config.master_lcore); > + > + eal_thread_dump_affinity(cpuset, CPU_STR_LEN); > + > + RTE_LOG(DEBUG, EAL, "Master lcore %u is ready (tid=%p;cpuset=[%s])\n", > + rte_config.master_lcore, thread_id, cpuset); > + > if (rte_eal_dev_init() < 0) > rte_panic("Cannot init pmd devices\n"); > > @@ -532,8 +537,6 @@ rte_eal_init(int argc, char **argv) > rte_panic("Cannot create thread\n"); > } > > - eal_thread_init_master(rte_config.master_lcore); > - > /* > * Launch a dummy function on all slave lcores, so that master lcore > * knows they are all ready when this function returns. I wonder if changing this may have an impact on third-party drivers that already use a management thread. Before the patch, the init() function of the external library was called with default affinities, and now it's called with the affinity from master lcore. I think it should at least be noticed in the commit log. Why are you doing this change? (I don't say it's a bad change, but I don't understand why you are doing it here) > diff --git a/lib/librte_eal/bsdapp/eal/eal_thread.c b/lib/librte_eal/bsdapp/eal/eal_thread.c > index d0c077b..5b16302 100644 > --- a/lib/librte_eal/bsdapp/eal/eal_thread.c > +++ b/lib/librte_eal/bsdapp/eal/eal_thread.c > @@ -103,55 +103,27 @@ eal_thread_set_affinity(void) > { > int s; > pthread_t thread; > - > -/* > - * According to the section VERSIONS of the CPU_ALLOC man page: > - * > - * The CPU_ZERO(), CPU_SET(), CPU_CLR(), and CPU_ISSET() macros were added > - * in glibc 2.3.3. > - * > - * CPU_COUNT() first appeared in glibc 2.6. > - * > - * CPU_AND(), CPU_OR(), CPU_XOR(), CPU_EQUAL(), CPU_ALLOC(), > - * CPU_ALLOC_SIZE(), CPU_FREE(), CPU_ZERO_S(), CPU_SET_S(), CPU_CLR_S(), > - * CPU_ISSET_S(), CPU_AND_S(), CPU_OR_S(), CPU_XOR_S(), and CPU_EQUAL_S() > - * first appeared in glibc 2.7. > - */ > -#if defined(CPU_ALLOC) > - size_t size; > - cpu_set_t *cpusetp; > - > - cpusetp = CPU_ALLOC(RTE_MAX_LCORE); > - if (cpusetp == NULL) { > - RTE_LOG(ERR, EAL, "CPU_ALLOC failed\n"); > - return -1; > - } > - > - size = CPU_ALLOC_SIZE(RTE_MAX_LCORE); > - CPU_ZERO_S(size, cpusetp); > - CPU_SET_S(rte_lcore_id(), size, cpusetp); > + unsigned lcore_id = rte_lcore_id(); > > thread = pthread_self(); > - s = pthread_setaffinity_np(thread, size, cpusetp); > + s = pthread_setaffinity_np(thread, sizeof(cpuset_t), > + &lcore_config[lcore_id].cpuset); > if (s != 0) { > RTE_LOG(ERR, EAL, "pthread_setaffinity_np failed\n"); > - CPU_FREE(cpusetp); > return -1; > } > > - CPU_FREE(cpusetp); > -#else /* CPU_ALLOC */ > - cpuset_t cpuset; > - CPU_ZERO( &cpuset ); > - CPU_SET( rte_lcore_id(), &cpuset ); > + /* acquire system unique id */ > + rte_gettid(); As suggested in the previous patch, I think having rte_init_tid() would be clearer here. > + > + /* store socket_id in TLS for quick access */ > + RTE_PER_LCORE(_socket_id) = > + eal_cpuset_socket_id(&lcore_config[lcore_id].cpuset); > + > + CPU_COPY(&lcore_config[lcore_id].cpuset, &RTE_PER_LCORE(_cpuset)); > + > + lcore_config[lcore_id].socket_id = RTE_PER_LCORE(_socket_id); > > - thread = pthread_self(); > - s = pthread_setaffinity_np(thread, sizeof( cpuset ), &cpuset); > - if (s != 0) { > - RTE_LOG(ERR, EAL, "pthread_setaffinity_np failed\n"); > - return -1; > - } > -#endif You are removing a lot of code that was using CPU_ALLOC(). Are we sure that the cpuset_t type is large enough to store all the CPUs? It looks the current value of CPU_SETSIZE is 1024 now, but I wonder if this code was written when this value was lower. Could you check if it can happen today (maybe with an old libc)? A problem can occur if the size of cpuset_t is lower that the size of RTE_MAX_LCORE. Regards, Olivier