From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtpout.efficios.com (smtpout.efficios.com [167.114.26.122]) by sourceware.org (Postfix) with ESMTPS id BD7223858C5E for ; Wed, 17 May 2023 15:27:05 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org BD7223858C5E Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=efficios.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=efficios.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=efficios.com; s=smtpout1; t=1684337224; bh=cGY+UUiS0WxsYW24i8f6zUJg+b2UGm/oIzYRyqAGABQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xJVyQm7GdpTCkFgl5YFT51SZEn4RQShO5JKmoP4KqC6BkFLube50vwhpFwOY/n/s2 DO7VeKFwt9vnBWPd2OjzuULKWw0xMd3AdrBR1R4ts2sGCjsEYEnVgurvrvZvLHHHPZ gCaMCjEFGlI3+lLXub5gTl9TAqIEe4NIT3OAuWjzmXBMZV0t7tLiHW18Ai+jIwUV/i w5wbQqzRrKevyVI8TyZgcTq4vIXWS85zvCR7AEywByqoJ/OL9qe9ZaCkTJJWLO8hAi um0Nw0ZLy0DpWzOAZYKjBDH/vRGmO6eWQxAANn9/74b+NtfaGEadt5DYLjmg/OSdqx YR32xMs+jOIEw== Received: from localhost.localdomain (192-222-143-198.qc.cable.ebox.net [192.222.143.198]) by smtpout.efficios.com (Postfix) with ESMTPSA id 4QLxmS1S00z12Mc; Wed, 17 May 2023 11:27:04 -0400 (EDT) From: Mathieu Desnoyers To: Peter Zijlstra Cc: linux-kernel@vger.kernel.org, Thomas Gleixner , "Paul E . McKenney" , Boqun Feng , "H . Peter Anvin" , Paul Turner , linux-api@vger.kernel.org, Christian Brauner , Florian Weimer , David.Laight@ACULAB.COM, carlos@redhat.com, Peter Oskolkov , Alexander Mikhalitsyn , Chris Kennelly , Ingo Molnar , Darren Hart , Davidlohr Bueso , =?UTF-8?q?Andr=C3=A9=20Almeida?= , libc-alpha@sourceware.org, Steven Rostedt , Jonathan Corbet , Mathieu Desnoyers Subject: [RFC PATCH 2/4] selftests/rseq: Add sched_state rseq field and getter Date: Wed, 17 May 2023 11:26:52 -0400 Message-Id: <20230517152654.7193-3-mathieu.desnoyers@efficios.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230517152654.7193-1-mathieu.desnoyers@efficios.com> References: <20230517152654.7193-1-mathieu.desnoyers@efficios.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-11.7 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,GIT_PATCH_0,SPF_HELO_NONE,SPF_PASS,TXREP,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: Extend struct rseq in the rseq selftests to include the sched_state field. Implement a getter function for this field. Signed-off-by: Mathieu Desnoyers --- tools/testing/selftests/rseq/rseq-abi.h | 17 +++++++++++++++++ tools/testing/selftests/rseq/rseq.h | 5 +++++ 2 files changed, 22 insertions(+) diff --git a/tools/testing/selftests/rseq/rseq-abi.h b/tools/testing/selftests/rseq/rseq-abi.h index fb4ec8a75dd4..15ec333e9eec 100644 --- a/tools/testing/selftests/rseq/rseq-abi.h +++ b/tools/testing/selftests/rseq/rseq-abi.h @@ -37,6 +37,13 @@ enum rseq_abi_cs_flags { (1U << RSEQ_ABI_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT), }; +enum rseq_sched_state { + /* + * Task is currently running on a CPU if bit is set. + */ + RSEQ_SCHED_STATE_ON_CPU = (1U << 0), +}; + /* * struct rseq_abi_cs is aligned on 4 * 8 bytes to ensure it is always * contained within a single cache-line. It is usually declared as @@ -164,6 +171,16 @@ struct rseq_abi { */ __u32 mm_cid; + /* + * Restartable sequences sched_state field. Updated by the kernel. Read + * by user-space with single-copy atomicity semantics. This fields can + * be read by any userspace thread. Aligned on 32-bit. Contains a + * bitmask of enum rseq_sched_state. This field is provided as a hint + * by the scheduler, and requires that the page holding struct rseq is + * faulted-in for the state update to be performed by the scheduler. + */ + __u32 sched_state; + /* * Flexible array member at end of structure, after last feature field. */ diff --git a/tools/testing/selftests/rseq/rseq.h b/tools/testing/selftests/rseq/rseq.h index d7364ea4d201..348e9385cb2b 100644 --- a/tools/testing/selftests/rseq/rseq.h +++ b/tools/testing/selftests/rseq/rseq.h @@ -236,6 +236,11 @@ static inline void rseq_prepare_unload(void) rseq_clear_rseq_cs(); } +static inline uint32_t rseq_current_sched_state(void) +{ + return RSEQ_ACCESS_ONCE(rseq_get_abi()->sched_state); +} + static inline __attribute__((always_inline)) int rseq_cmpeqv_storev(enum rseq_mo rseq_mo, enum rseq_percpu_mode percpu_mode, intptr_t *v, intptr_t expect, -- 2.25.1