{"id":2227795,"url":"http://patchwork.ozlabs.org/api/1.1/patches/2227795/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20260424-force_rcu-v4-1-feccfaca0568@rsg.ci.i.u-tokyo.ac.jp/","project":{"id":14,"url":"http://patchwork.ozlabs.org/api/1.1/projects/14/?format=json","name":"QEMU Development","link_name":"qemu-devel","list_id":"qemu-devel.nongnu.org","list_email":"qemu-devel@nongnu.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20260424-force_rcu-v4-1-feccfaca0568@rsg.ci.i.u-tokyo.ac.jp>","date":"2026-04-24T09:27:06","name":"[v4,1/6] futex: Add qemu_futex_timedwait()","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"5906ab65db6e4b8bc3757184e6a6f671d75a72b9","submitter":{"id":90980,"url":"http://patchwork.ozlabs.org/api/1.1/people/90980/?format=json","name":"Akihiko Odaki","email":"odaki@rsg.ci.i.u-tokyo.ac.jp"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20260424-force_rcu-v4-1-feccfaca0568@rsg.ci.i.u-tokyo.ac.jp/mbox/","series":[{"id":501326,"url":"http://patchwork.ozlabs.org/api/1.1/series/501326/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/list/?series=501326","date":"2026-04-24T09:27:07","name":"virtio-gpu: Force RCU when unmapping blob","version":4,"mbox":"http://patchwork.ozlabs.org/series/501326/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2227795/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2227795/checks/","tags":{},"headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=fail reason=\"key not found in DNS\" header.d=rsg.ci.i.u-tokyo.ac.jp\n header.i=@rsg.ci.i.u-tokyo.ac.jp header.a=rsa-sha256 header.s=rs20250326\n header.b=M6rzkSbA;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org\n (client-ip=209.51.188.17; helo=lists1p.gnu.org;\n envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org;\n receiver=patchwork.ozlabs.org)"],"Received":["from lists1p.gnu.org (lists1p.gnu.org [209.51.188.17])\n\t(using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4g271v6Lrbz1xvV\n\tfor ; Fri, 24 Apr 2026 19:28:51 +1000 (AEST)","from localhost ([::1] helo=lists1p.gnu.org)\n\tby lists1p.gnu.org with esmtp (Exim 4.90_1)\n\t(envelope-from )\n\tid 1wGCpg-0008Em-1a; Fri, 24 Apr 2026 05:28:20 -0400","from eggs.gnu.org ([2001:470:142:3::10])\n by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)\n (Exim 4.90_1) (envelope-from )\n id 1wGCp5-0007QI-1m\n for qemu-devel@nongnu.org; Fri, 24 Apr 2026 05:27:43 -0400","from www3579.sakura.ne.jp ([49.212.243.89])\n by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)\n (Exim 4.90_1) (envelope-from )\n id 1wGCp0-0007aB-1L\n for qemu-devel@nongnu.org; Fri, 24 Apr 2026 05:27:42 -0400","from h205.csg.ci.i.u-tokyo.ac.jp (h205.csg.ci.i.u-tokyo.ac.jp\n [133.11.54.205]) (authenticated bits=0)\n by www3579.sakura.ne.jp (8.16.1/8.16.1) with ESMTPSA id 63O9RHId004358\n (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO);\n Fri, 24 Apr 2026 18:27:26 +0900 (JST)\n (envelope-from odaki@rsg.ci.i.u-tokyo.ac.jp)"],"DKIM-Signature":"a=rsa-sha256; bh=2lrFVsOwSY/n/C0RCLf6Y19MCgXdoAnnxYob5thdabU=;\n c=relaxed/relaxed; d=rsg.ci.i.u-tokyo.ac.jp;\n h=From:Message-Id:To:Subject:Date;\n s=rs20250326; t=1777022846; v=1;\n b=M6rzkSbAKaf0mJ0HK6MsyeudpxJReB/TfL3EMWS4U4j+Nmhn72rjPxMshnG5gh02\n VC8xNrwfAzFdOGE4WoIeXj9bDOYzqxw0iUnTv9cEdFfo+56UmCs+kC5N2GVOL3B/\n Rw/DGwda5xxBkhBkyrZzm3MvikNtXl6Da9uspDKi8Pl31YHtZml/pONaa5Lz1/GF\n /Tf5jYmkUJzE/hypHnjFKzViUYFTznmfx8sGCbXkv46+g9xwo1mdD9c17xeFw77T\n u375xMbHIKB99aIDRFmKJ6u7TmPoTfW6rNFo4kZOxiqA6PiGNKHrBo7dLPX+c64l\n FdqK0Rxv0P5j24bnzJXVXA==","From":"Akihiko Odaki ","Date":"Fri, 24 Apr 2026 18:27:06 +0900","Subject":"[PATCH v4 1/6] futex: Add qemu_futex_timedwait()","MIME-Version":"1.0","Content-Type":"text/plain; charset=\"utf-8\"","Content-Transfer-Encoding":"7bit","Message-Id":"<20260424-force_rcu-v4-1-feccfaca0568@rsg.ci.i.u-tokyo.ac.jp>","References":"<20260424-force_rcu-v4-0-feccfaca0568@rsg.ci.i.u-tokyo.ac.jp>","In-Reply-To":"<20260424-force_rcu-v4-0-feccfaca0568@rsg.ci.i.u-tokyo.ac.jp>","To":"qemu-devel@nongnu.org, Dmitry Osipenko ","Cc":"Paolo Bonzini ,\n \"Michael S. Tsirkin\" ,\n =?utf-8?q?Alex_Benn=C3=A9e?= ,\n Akihiko Odaki ","X-Mailer":"b4 0.16-dev-16047","Received-SPF":"pass client-ip=49.212.243.89;\n envelope-from=odaki@rsg.ci.i.u-tokyo.ac.jp; helo=www3579.sakura.ne.jp","X-Spam_score_int":"-16","X-Spam_score":"-1.7","X-Spam_bar":"-","X-Spam_report":"(-1.7 / 5.0 requ) BAYES_00=-1.9, DKIM_INVALID=0.1,\n DKIM_SIGNED=0.1, SPF_HELO_NONE=0.001,\n SPF_PASS=-0.001 autolearn=no autolearn_force=no","X-Spam_action":"no action","X-BeenThere":"qemu-devel@nongnu.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"qemu development ","List-Unsubscribe":",\n ","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n ","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org"},"content":"qemu_futex_timedwait() is equivalent to qemu_futex_wait(), except it has\nan absolute timeout.\n\nSigned-off-by: Akihiko Odaki \nTested-by: Dmitry Osipenko \n---\n include/qemu/futex.h | 36 +++++++++++++++++++++++++++++++-----\n 1 file changed, 31 insertions(+), 5 deletions(-)","diff":"diff --git a/include/qemu/futex.h b/include/qemu/futex.h\nindex 607613eec835..3f3b55008f61 100644\n--- a/include/qemu/futex.h\n+++ b/include/qemu/futex.h\n@@ -24,13 +24,19 @@\n #ifndef QEMU_FUTEX_H\n #define QEMU_FUTEX_H\n \n+#include \"qemu/timer.h\"\n #define HAVE_FUTEX\n \n #ifdef CONFIG_LINUX\n #include \n #include \n+#include \n \n+#ifdef __NR_futex_time64\n+#define qemu_futex(...) syscall(__NR_futex_time64, __VA_ARGS__)\n+#else\n #define qemu_futex(...) syscall(__NR_futex, __VA_ARGS__)\n+#endif\n \n static inline void qemu_futex_wake_all(void *f)\n {\n@@ -42,18 +48,28 @@ static inline void qemu_futex_wake_single(void *f)\n qemu_futex(f, FUTEX_WAKE, 1, NULL, NULL, 0);\n }\n \n-static inline void qemu_futex_wait(void *f, unsigned val)\n+static inline bool qemu_futex_timedwait(void *f, unsigned val, int64_t ns)\n {\n- while (qemu_futex(f, FUTEX_WAIT, (int) val, NULL, NULL, 0)) {\n+ struct __kernel_timespec ts;\n+ uint32_t bitset = FUTEX_BITSET_MATCH_ANY;\n+\n+ ts.tv_sec = ns / NANOSECONDS_PER_SECOND;\n+ ts.tv_nsec = ns % NANOSECONDS_PER_SECOND;\n+\n+ while (qemu_futex(f, FUTEX_WAIT_BITSET, (int) val, &ts, NULL, bitset)) {\n switch (errno) {\n case EWOULDBLOCK:\n- return;\n+ return true;\n case EINTR:\n break; /* get out of switch and retry */\n+ case ETIMEDOUT:\n+ return false;\n default:\n abort();\n }\n }\n+\n+ return true;\n }\n #elif defined(CONFIG_WIN32)\n #include \n@@ -68,12 +84,22 @@ static inline void qemu_futex_wake_single(void *f)\n WakeByAddressSingle(f);\n }\n \n-static inline void qemu_futex_wait(void *f, unsigned val)\n+static inline bool qemu_futex_timedwait(void *f, unsigned val, int64_t ns)\n {\n- WaitOnAddress(f, &val, sizeof(val), INFINITE);\n+ int64_t now = get_clock();\n+ DWORD duration = MIN((ns - now) / SCALE_MS, INFINITE);\n+\n+ return ns > now && WaitOnAddress(f, &val, sizeof(val), duration);\n }\n #else\n #undef HAVE_FUTEX\n #endif\n \n+#ifdef HAVE_FUTEX\n+static inline void qemu_futex_wait(void *f, unsigned val)\n+{\n+ qemu_futex_timedwait(f, val, INT64_MAX);\n+}\n+#endif\n+\n #endif /* QEMU_FUTEX_H */\n","prefixes":["v4","1/6"]}