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 091A745C82; Tue, 5 Nov 2024 04:17:49 +0100 (CET) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id C7562427B1; Tue, 5 Nov 2024 04:17:41 +0100 (CET) Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by mails.dpdk.org (Postfix) with ESMTP id EFE274279B for ; Tue, 5 Nov 2024 04:17:36 +0100 (CET) Received: by linux.microsoft.com (Postfix, from userid 1213) id 269C42126CA2; Mon, 4 Nov 2024 19:17:36 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 269C42126CA2 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1730776656; bh=mRU57TuyHutGPHe8HgWJGK8JboztYs7XNZrc+5mlAu8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Rmv8x8vfsIDXNdmSa0Uj5I5GIbx9zoVAVmgLuWKdXoeFKXYHdP5IdOdRyt2NYrsUk sqWQA6QpjagrPVnw6Wequ8Aq9NktWaJ1pVWYAJ2ZmwepXZtsjmT7qZUaIViHvFfUvw TmAkx5Rg9wRXe3qwMXJGWwm6qhcOB8OgtVnOQWcg= From: Andre Muezerie To: stephen@networkplumber.org Cc: aman.deep.singh@intel.com, anatoly.burakov@intel.com, andrew.rybchenko@oktetlabs.ru, bruce.richardson@intel.com, dev@dpdk.org, dmitry.kozliuk@gmail.com, dsosnowski@nvidia.com, fanzhang.oss@gmail.com, fengchengwen@huawei.com, ferruh.yigit@amd.com, gakhil@marvell.com, harry.van.haaren@intel.com, hkalra@marvell.com, honnappa.nagarahalli@arm.com, hujiayu.hu@foxmail.com, jingjing.wu@intel.com, kevin.laatz@intel.com, konstantin.v.ananyev@yandex.ru, matan@nvidia.com, mb@smartsharesystems.com, orika@nvidia.com, pallavi.kadam@intel.com, reshma.pattan@intel.com, roretzla@linux.microsoft.com, sameh.gobriel@intel.com, suanmingm@nvidia.com, thomas@monjalon.net, vfialko@marvell.com, viacheslavo@nvidia.com, vladimir.medvedkin@intel.com, yipeng1.wang@intel.com, Konstantin Ananyev Subject: [PATCH v4 02/19] eal/linux: remove use of VLAs Date: Mon, 4 Nov 2024 19:15:36 -0800 Message-Id: <1730776553-31277-3-git-send-email-andremue@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1730776553-31277-1-git-send-email-andremue@linux.microsoft.com> References: <1713397319-26135-1-git-send-email-roretzla@linux.microsoft.com> <1730776553-31277-1-git-send-email-andremue@linux.microsoft.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 From: Konstantin Ananyev 1) ./lib/eal/linux/eal_interrupts.c:1073:16 : warning: ISO C90 forbids variable length array ‘events’ eal_intr_handle_interrupts() is called by eal_intr_thread_main() so it seems ok to simply alloc space for events from heap and reuse the same buffer through the life of the thread. 2) ./lib/eal/linux/eal_interrupts.c:1319:16 : warning: ISO C90 forbids variable length array ‘evs’ make eal_epoll_wait() use a fixed size array and use it though multiple iterations to process up to @maxevents events. Note that technically it is not one to one replacement, as here we might reduce number of events returned by first call to epoll_wait(..., timeout); Signed-off-by: Konstantin Ananyev --- lib/eal/linux/eal_interrupts.c | 59 ++++++++++++++++++++++++++++++---- 1 file changed, 52 insertions(+), 7 deletions(-) diff --git a/lib/eal/linux/eal_interrupts.c b/lib/eal/linux/eal_interrupts.c index 6436f796eb..d62bb80a3e 100644 --- a/lib/eal/linux/eal_interrupts.c +++ b/lib/eal/linux/eal_interrupts.c @@ -34,6 +34,8 @@ #define EAL_INTR_EPOLL_WAIT_FOREVER (-1) #define NB_OTHER_INTR 1 +#define MAX_ITER_EVNUM RTE_EVENT_ETH_INTR_RING_SIZE + static RTE_DEFINE_PER_LCORE(int, _epfd) = -1; /**< epoll fd per thread */ /** @@ -1068,9 +1070,9 @@ eal_intr_process_interrupts(struct epoll_event *events, int nfds) * void */ static void -eal_intr_handle_interrupts(int pfd, unsigned totalfds) +eal_intr_handle_interrupts(int pfd, struct epoll_event events[], + unsigned int totalfds) { - struct epoll_event events[totalfds]; int nfds = 0; for(;;) { @@ -1106,6 +1108,12 @@ eal_intr_handle_interrupts(int pfd, unsigned totalfds) static __rte_noreturn uint32_t eal_intr_thread_main(__rte_unused void *arg) { + uint32_t n, nb_event; + struct epoll_event *events, *p; + + nb_event = 0; + events = NULL; + /* host thread, never break out */ for (;;) { /* build up the epoll fd with all descriptors we are to @@ -1159,8 +1167,23 @@ eal_intr_thread_main(__rte_unused void *arg) numfds++; } rte_spinlock_unlock(&intr_lock); + + /* alloc space for events, when necessary */ + if (numfds > nb_event) { + n = numfds + MAX_ITER_EVNUM; + p = realloc(events, n * sizeof(events[0])); + if (p == NULL) { + EAL_LOG(ERR, "failed to allocate %u events", + numfds); + numfds = nb_event; + } else { + nb_event = n; + events = p; + } + } + /* serve the interrupt */ - eal_intr_handle_interrupts(pfd, numfds); + eal_intr_handle_interrupts(pfd, events, numfds); /** * when we return, we need to rebuild the @@ -1168,6 +1191,8 @@ eal_intr_thread_main(__rte_unused void *arg) */ close(pfd); } + + free(events); } int @@ -1316,8 +1341,9 @@ static int eal_epoll_wait(int epfd, struct rte_epoll_event *events, int maxevents, int timeout, bool interruptible) { - struct epoll_event evs[maxevents]; int rc; + uint32_t i, k, n, num; + struct epoll_event evs[MAX_ITER_EVNUM]; if (!events) { EAL_LOG(ERR, "rte_epoll_event can't be NULL"); @@ -1328,12 +1354,31 @@ eal_epoll_wait(int epfd, struct rte_epoll_event *events, if (epfd == RTE_EPOLL_PER_THREAD) epfd = rte_intr_tls_epfd(); + num = maxevents; + n = RTE_MIN(RTE_DIM(evs), num); + + /* Process events in chunks of MAX_ITER_EVNUM */ + while (1) { - rc = epoll_wait(epfd, evs, maxevents, timeout); + rc = epoll_wait(epfd, evs, n, timeout); if (likely(rc > 0)) { + /* epoll_wait has at least one fd ready to read */ - rc = eal_epoll_process_event(evs, rc, events); - break; + for (i = 0, k = 0; rc > 0;) { + k += rc; + rc = eal_epoll_process_event(evs, rc, + events + i); + i += rc; + + /* + * try to read more events that are already + * available (up to maxevents in total). + */ + n = RTE_MIN(RTE_DIM(evs), num - k); + rc = (n == 0) ? 0 : epoll_wait(epfd, evs, n, 0); + } + return i; + } else if (rc < 0) { if (errno == EINTR) { if (interruptible) -- 2.34.1