From patchwork Thu Apr 18 20:02:25 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Tyler Retzlaff X-Patchwork-Id: 139500 X-Patchwork-Delegate: thomas@monjalon.net Return-Path: X-Original-To: patchwork@inbox.dpdk.org Delivered-To: patchwork@inbox.dpdk.org Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 44D3543EA8; Thu, 18 Apr 2024 22:03:16 +0200 (CEST) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id D1F2E4067D; Thu, 18 Apr 2024 22:02:51 +0200 (CEST) Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by mails.dpdk.org (Postfix) with ESMTP id 14F2440272 for ; Thu, 18 Apr 2024 22:02:45 +0200 (CEST) Received: by linux.microsoft.com (Postfix, from userid 1086) id 008D120FD921; Thu, 18 Apr 2024 13:02:43 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 008D120FD921 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1713470564; bh=eATH/i+nEf7wfqbsClgomcbe34PUBvVsJ2Vxj3rogDo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kDhxFNSXw/524InRr44wED7p8pLiM9v5+ZNVRgaEo2XDtkTmekQCJrT6yFKhcS2wI uzyqq9XO45H6RANOJGu4OwPBWuvzwvNsdHgnqvDvsJAa6AgMFTdGBa08Cgcx32HBAH eKcg9g6zBhH7P4tDvssamRpTyEdkQfYjBwOYTLnI= From: Tyler Retzlaff To: dev@dpdk.org Cc: =?utf-8?q?Morten_Br=C3=B8rup?= , Akhil Goyal , Aman Singh , Anatoly Burakov , Andrew Rybchenko , Bruce Richardson , Chengwen Feng , Dariusz Sosnowski , Dmitry Kozlyuk , Fan Zhang , Ferruh Yigit , Harman Kalra , Harry van Haaren , Honnappa Nagarahalli , Jiayu Hu , Jingjing Wu , Kevin Laatz , Konstantin Ananyev , Matan Azrad , Ori Kam , Pallavi Kadam , Reshma Pattan , Sameh Gobriel , Suanming Mou , Thomas Monjalon , Tyler Retzlaff , Viacheslav Ovsiienko , Vladimir Medvedkin , Volodymyr Fialko , Yipeng Wang , Konstantin Ananyev Subject: [PATCH v2 02/19] eal/linux: remove use of VLAs Date: Thu, 18 Apr 2024 13:02:25 -0700 Message-Id: <1713470562-17415-3-git-send-email-roretzla@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1713470562-17415-1-git-send-email-roretzla@linux.microsoft.com> References: <1713397319-26135-1-git-send-email-roretzla@linux.microsoft.com> <1713470562-17415-1-git-send-email-roretzla@linux.microsoft.com> MIME-Version: 1.0 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() to use fixed size array and use it though multiple iterations to preocess upt to @maxevents events. Note that techically it is not one to one raplacement, 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 6436f79..58e3b8e 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 @@ struct rte_intr_source { * void */ static void -eal_intr_handle_interrupts(int pfd, unsigned totalfds) +eal_intr_handle_interrupts(int pfd, struct epoll_event events[], + unsigned totalfds) { - struct epoll_event events[totalfds]; int nfds = 0; for(;;) { @@ -1106,6 +1108,12 @@ struct rte_intr_source { 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 @@ struct rte_intr_source { 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 @@ struct rte_intr_source { */ close(pfd); } + + free(events); } int @@ -1316,8 +1341,9 @@ struct rte_intr_source { 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 @@ struct rte_intr_source { 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)