From nobody Tue Feb 10 05:18:02 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=reject dis=none) header.from=rsg.ci.i.u-tokyo.ac.jp Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1768455607602165.33608575089352; Wed, 14 Jan 2026 21:40:07 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vgG4x-0006uD-Q5; Thu, 15 Jan 2026 00:39:31 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vgG4t-0006ru-Oi for qemu-devel@nongnu.org; Thu, 15 Jan 2026 00:39:27 -0500 Received: from www3579.sakura.ne.jp ([49.212.243.89]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vgG4n-0004fI-Kh for qemu-devel@nongnu.org; Thu, 15 Jan 2026 00:39:26 -0500 Received: from h205.csg.ci.i.u-tokyo.ac.jp (h205.csg.ci.i.u-tokyo.ac.jp [133.11.54.205]) (authenticated bits=0) by www3579.sakura.ne.jp (8.16.1/8.16.1) with ESMTPSA id 60F5cwVb061416 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Thu, 15 Jan 2026 14:39:07 +0900 (JST) (envelope-from odaki@rsg.ci.i.u-tokyo.ac.jp) DKIM-Signature: a=rsa-sha256; bh=TbmQfRhW7tk1w8y2oJ/yjOqATkEcmBrVR6/713ng5E4=; c=relaxed/relaxed; d=rsg.ci.i.u-tokyo.ac.jp; h=From:Date:Subject:Message-Id:To; s=rs20250326; t=1768455547; v=1; b=Xs25c2brwstefH6vbLHiQ39CrFh/AWaBN1Bv5jKzhhFfOxw/mB1fuwaMiH7luymO l3G/uKKS3wO3MdbeZNt2x8ExcXZcbQDT0t3N0QYRzLPUq8RHprHti5t0NhEiTHUc O1zyO15vDQzyjblladXDOSzWs/CW47+7KNN5xtOyCsd0ds8mxAu7ktIl8gqDNMhE wL5g9uIVjFtarzC9ja7evnw322RrfxZTB0NYSOm2RFtgrNK/8NPtnbWwMN+DHIDA eT3v5IPoGFnX2XkhDRdOwtDfnL0kEacYozX7s5n76BWBqD6dVRUWxAKroB2BBqwQ iJLTZlsD2MBwRNRBLdT23A== From: Akihiko Odaki Date: Thu, 15 Jan 2026 14:38:50 +0900 Subject: [PATCH v3 1/5] futex: Add qemu_futex_timedwait() MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260115-force_rcu-v3-1-1f8bfaff4815@rsg.ci.i.u-tokyo.ac.jp> References: <20260115-force_rcu-v3-0-1f8bfaff4815@rsg.ci.i.u-tokyo.ac.jp> In-Reply-To: <20260115-force_rcu-v3-0-1f8bfaff4815@rsg.ci.i.u-tokyo.ac.jp> To: qemu-devel@nongnu.org, Dmitry Osipenko Cc: Paolo Bonzini , "Michael S. Tsirkin" , =?utf-8?q?Alex_Benn=C3=A9e?= , Akihiko Odaki X-Mailer: b4 0.15-dev-179e8 Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=49.212.243.89; 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, DKIM_SIGNED=0.1, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=0.001, 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: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1768455610246158500 qemu_futex_timedwait() is equivalent to qemu_futex_wait(), except it has an absolute timeout. Signed-off-by: Akihiko Odaki Tested-by: Dmitry Osipenko --- include/qemu/futex.h | 36 +++++++++++++++++++++++++++++++----- 1 file changed, 31 insertions(+), 5 deletions(-) diff --git a/include/qemu/futex.h b/include/qemu/futex.h index 607613eec835..3f3b55008f61 100644 --- a/include/qemu/futex.h +++ b/include/qemu/futex.h @@ -24,13 +24,19 @@ #ifndef QEMU_FUTEX_H #define QEMU_FUTEX_H =20 +#include "qemu/timer.h" #define HAVE_FUTEX =20 #ifdef CONFIG_LINUX #include #include +#include =20 +#ifdef __NR_futex_time64 +#define qemu_futex(...) syscall(__NR_futex_time64, __VA_ARGS_= _) +#else #define qemu_futex(...) syscall(__NR_futex, __VA_ARGS__) +#endif =20 static inline void qemu_futex_wake_all(void *f) { @@ -42,18 +48,28 @@ static inline void qemu_futex_wake_single(void *f) qemu_futex(f, FUTEX_WAKE, 1, NULL, NULL, 0); } =20 -static inline void qemu_futex_wait(void *f, unsigned val) +static inline bool qemu_futex_timedwait(void *f, unsigned val, int64_t ns) { - while (qemu_futex(f, FUTEX_WAIT, (int) val, NULL, NULL, 0)) { + struct __kernel_timespec ts; + uint32_t bitset =3D FUTEX_BITSET_MATCH_ANY; + + ts.tv_sec =3D ns / NANOSECONDS_PER_SECOND; + ts.tv_nsec =3D ns % NANOSECONDS_PER_SECOND; + + while (qemu_futex(f, FUTEX_WAIT_BITSET, (int) val, &ts, NULL, bitset))= { switch (errno) { case EWOULDBLOCK: - return; + return true; case EINTR: break; /* get out of switch and retry */ + case ETIMEDOUT: + return false; default: abort(); } } + + return true; } #elif defined(CONFIG_WIN32) #include @@ -68,12 +84,22 @@ static inline void qemu_futex_wake_single(void *f) WakeByAddressSingle(f); } =20 -static inline void qemu_futex_wait(void *f, unsigned val) +static inline bool qemu_futex_timedwait(void *f, unsigned val, int64_t ns) { - WaitOnAddress(f, &val, sizeof(val), INFINITE); + int64_t now =3D get_clock(); + DWORD duration =3D MIN((ns - now) / SCALE_MS, INFINITE); + + return ns > now && WaitOnAddress(f, &val, sizeof(val), duration); } #else #undef HAVE_FUTEX #endif =20 +#ifdef HAVE_FUTEX +static inline void qemu_futex_wait(void *f, unsigned val) +{ + qemu_futex_timedwait(f, val, INT64_MAX); +} +#endif + #endif /* QEMU_FUTEX_H */ --=20 2.52.0