From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 20F9F41C2A; Tue, 7 Feb 2023 07:01:02 +0100 (CET) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id A6F7440ED9; Tue, 7 Feb 2023 07:01:01 +0100 (CET) Received: from mail-ua1-f49.google.com (mail-ua1-f49.google.com [209.85.222.49]) by mails.dpdk.org (Postfix) with ESMTP id E84C840E6E; Tue, 7 Feb 2023 07:01:00 +0100 (CET) Received: by mail-ua1-f49.google.com with SMTP id u3so2590579uae.0; Mon, 06 Feb 2023 22:01:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=eFdDxEckg+wjs9ZkPx0woSvofTFew2CHbCfOY7uC9xM=; b=ZrialEFInnr9atqr8YKbeQm3JeExxmJOKUx4RsGoEz6FEYelOT4FCqic5bFZMuje9c PevPsSNQq/IYVAWIf6y15R+HCNsZ/nWyo9i4eBtDx24OCN0Ukx+JiUh5YCJEavoPYGGC 9AWEjcHOK749Dc8eb0FbFBy0NYLsVpLquhDurdLn6BEWaEEufaQegY5iKwp+1mbgsSyt +qMpALtCCw76ulWqhYcvmgD/id8wV1kuMp+Nj0NI2h9IiabdcwnpV/A7yycrNY3izaaA GWyoMRRmDmOeSj4aggFNGRTv8pm/zHWBYMuruFPdrtOFZ6w23wZgUjJvKoiBLIhQVP8N wcvA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=eFdDxEckg+wjs9ZkPx0woSvofTFew2CHbCfOY7uC9xM=; b=woQBwNj+F3uUNuijOGoGuBpJsmv/xfXOeLTbTaFHygbVtt7AH9zm1b6aUYB8J1X6Np ycb5r7f8SCpFTZdlsUqJff6mmWcH0k4wP2yGoe+dtwxiSPqthsi89btitYQzV9Etfen2 HSXK8M8DWDBd02cOb3jO31Bsfxilmb0wL36KFX2kUW+V674bZR1LGMfYFCx6yXpH1vqi zRT8EiguhLrKMISDpdM6YmIgOhHCLrb8oL5qHgraorSZf1JIM2alAXxdbuQQVlsVpX+U wUOZaT8iFH+jxVlLjkXwmnVt6O6eqILKu2ohz6yz3paYAXW+OW3WFIZrVIM11/LMhV7h PqEg== X-Gm-Message-State: AO0yUKVDhtl9tFSOg4MRvEoB9o3EQd1M3cnLZoWQv+lZmmVFODUuAUMf Kpd5L58727MIjvTENxUXDb4+PDgvTj8uJDPQI/nMXFB2hSM= X-Google-Smtp-Source: AK7set+NwHhX7DhNdooIbFpOATGG6aaDSqocCyLsTJaHAGZxP90pWGjitTzSsk8rDpJP1TT6OSEPQtnHeArY/8TyDEc= X-Received: by 2002:ab0:2401:0:b0:683:8d8f:2671 with SMTP id f1-20020ab02401000000b006838d8f2671mr389411uan.24.1675749660179; Mon, 06 Feb 2023 22:01:00 -0800 (PST) MIME-Version: 1.0 References: <20230124160945.3003303-1-erik.g.carrillo@intel.com> <20230124204555.3022361-1-erik.g.carrillo@intel.com> In-Reply-To: <20230124204555.3022361-1-erik.g.carrillo@intel.com> From: Jerin Jacob Date: Tue, 7 Feb 2023 11:30:33 +0530 Message-ID: Subject: Re: [PATCH v2] eventdev/timer: fix overflow issue To: Erik Gabriel Carrillo , Stephen Hemminger Cc: jerinj@marvell.com, dev@dpdk.org, stable@dpdk.org Content-Type: text/plain; charset="UTF-8" X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org On Wed, Jan 25, 2023 at 2:16 AM Erik Gabriel Carrillo wrote: > > The software timer adapter converts event timer timeout ticks to a > number of CPU cycles at which an rte_timer should expire. The > computation uses integer operations that can result in overflow. > > Use floating point operations instead to perform the computation, and > convert the final result back to an integer type when returning. Also > move the logic that checks the timeout range into the function that > performs the above computation. > > Fixes: 6750b21bd6af ("eventdev: add default software timer adapter") > Cc: stable@dpdk.org > > Signed-off-by: Erik Gabriel Carrillo > --- > v2: > * Fix implicit int to float conversion build warning on Clang Not yet addressed the @Stephen Hemminger comments on using of rte_reciprocal. Also means to check what compute can be moved to slowpath. Marking as "Change requested", Looking for next version. > > lib/eventdev/rte_event_timer_adapter.c | 71 ++++++++++++-------------- > 1 file changed, 34 insertions(+), 37 deletions(-) > > diff --git a/lib/eventdev/rte_event_timer_adapter.c b/lib/eventdev/rte_event_timer_adapter.c > index d357f7403a..2efeb73bce 100644 > --- a/lib/eventdev/rte_event_timer_adapter.c > +++ b/lib/eventdev/rte_event_timer_adapter.c > @@ -719,13 +719,28 @@ swtim_callback(struct rte_timer *tim) > } > } > > -static __rte_always_inline uint64_t > +static __rte_always_inline int > get_timeout_cycles(struct rte_event_timer *evtim, > - const struct rte_event_timer_adapter *adapter) > + const struct rte_event_timer_adapter *adapter, > + uint64_t *timeout_cycles) > { > struct swtim *sw = swtim_pmd_priv(adapter); > - uint64_t timeout_ns = evtim->timeout_ticks * sw->timer_tick_ns; > - return timeout_ns * rte_get_timer_hz() / NSECPERSEC; > + uint64_t timeout_nsecs; > + double cycles_per_nsec; > + > + cycles_per_nsec = (double)rte_get_timer_hz() / NSECPERSEC; > + > + timeout_nsecs = evtim->timeout_ticks * sw->timer_tick_ns; > + if (timeout_nsecs > sw->max_tmo_ns) > + return -1; > + if (timeout_nsecs < sw->timer_tick_ns) > + return -2; > + > + if (timeout_cycles) > + *timeout_cycles = (uint64_t)ceil(timeout_nsecs * > + cycles_per_nsec); > + > + return 0; > } > > /* This function returns true if one or more (adapter) ticks have occurred since > @@ -759,23 +774,6 @@ swtim_did_tick(struct swtim *sw) > return false; > } > > -/* Check that event timer timeout value is in range */ > -static __rte_always_inline int > -check_timeout(struct rte_event_timer *evtim, > - const struct rte_event_timer_adapter *adapter) > -{ > - uint64_t tmo_nsec; > - struct swtim *sw = swtim_pmd_priv(adapter); > - > - tmo_nsec = evtim->timeout_ticks * sw->timer_tick_ns; > - if (tmo_nsec > sw->max_tmo_ns) > - return -1; > - if (tmo_nsec < sw->timer_tick_ns) > - return -2; > - > - return 0; > -} > - > /* Check that event timer event queue sched type matches destination event queue > * sched type > */ > @@ -1195,21 +1193,6 @@ __swtim_arm_burst(const struct rte_event_timer_adapter *adapter, > break; > } > > - ret = check_timeout(evtims[i], adapter); > - if (unlikely(ret == -1)) { > - __atomic_store_n(&evtims[i]->state, > - RTE_EVENT_TIMER_ERROR_TOOLATE, > - __ATOMIC_RELAXED); > - rte_errno = EINVAL; > - break; > - } else if (unlikely(ret == -2)) { > - __atomic_store_n(&evtims[i]->state, > - RTE_EVENT_TIMER_ERROR_TOOEARLY, > - __ATOMIC_RELAXED); > - rte_errno = EINVAL; > - break; > - } > - > if (unlikely(check_destination_event_queue(evtims[i], > adapter) < 0)) { > __atomic_store_n(&evtims[i]->state, > @@ -1225,7 +1208,21 @@ __swtim_arm_burst(const struct rte_event_timer_adapter *adapter, > evtims[i]->impl_opaque[0] = (uintptr_t)tim; > evtims[i]->impl_opaque[1] = (uintptr_t)adapter; > > - cycles = get_timeout_cycles(evtims[i], adapter); > + ret = get_timeout_cycles(evtims[i], adapter, &cycles); > + if (unlikely(ret == -1)) { > + __atomic_store_n(&evtims[i]->state, > + RTE_EVENT_TIMER_ERROR_TOOLATE, > + __ATOMIC_RELAXED); > + rte_errno = EINVAL; > + break; > + } else if (unlikely(ret == -2)) { > + __atomic_store_n(&evtims[i]->state, > + RTE_EVENT_TIMER_ERROR_TOOEARLY, > + __ATOMIC_RELAXED); > + rte_errno = EINVAL; > + break; > + } > + > ret = rte_timer_alt_reset(sw->timer_data_id, tim, cycles, > type, lcore_id, NULL, evtims[i]); > if (ret < 0) { > -- > 2.23.0 >