From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8152C3FCB03; Thu, 7 May 2026 16:51:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778172678; cv=none; b=dLhVCiKdA4ET8xM+IdEdXOF+VV6D3oBldNI7QrALMql8a88wP+b5GMW4R3Sd8NYEWb84UZ7EXi8mLZN405TFevj9gjLmt3NhqYXDGvSDDtdviNetOF5tS53bBP0/x1JQWaryuFkY2cWYS78BD88P+Cyw/SPjdh8Gsle2eVAaXc4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778172678; c=relaxed/simple; bh=lr0xdIdDI31fTQQCHgc1R9osfRZceuX3vZywvp6dVSA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=pjeRC057g1P11v+PpGGstyvawaf5bEAOwIPlHCEleoHgiaPnUVOT7OuWssus16ZMITtU/vbUM9lCTSJdQL1hzpo53faY1+zpK4RSMJCxC2x7mO/A5L0Re9Pn9d/fdIy+5PxTroP1xkoWKhuOaAPjAj69Njkwketui2p6N0bz9Yo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=gxwVjtBO; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="gxwVjtBO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 27213C2BCB2; Thu, 7 May 2026 16:51:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778172678; bh=lr0xdIdDI31fTQQCHgc1R9osfRZceuX3vZywvp6dVSA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gxwVjtBOTNM9O1I5iekZ6Njngnqrny2aHNepyhjl+yvjE8dvnPeuyUk/m5cnWfYC7 eiHvlqawUCmjNyoTWeZ1ckPjcPsa2QQ0coRvqNHir2Ymo8b6U7wrCIIvheSNxXVWO8 kZIO0n98Rn55v0D95TuQzcpBWC/1JKAWCOmjcKFcT0KbPDg76sa/h3uh5xK6fmeQFL 6gevyrPrlkeVvX5lZlACWtNrSx1xo+c/dsi6nU1XBwqiWNMCemWScsnLmiD6fImU7g NJGUdmk6s8ic2WgSFQnowJl8B7gr3NiBWV6mpef/PdzR/KR/I42qtx4dNqNzOmP20d PK0ybr50l9P3A== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id D6D5ECE0863; Thu, 7 May 2026 09:51:17 -0700 (PDT) From: "Paul E. McKenney" To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com, rostedt@goodmis.org, Mathieu Desnoyers , "Paul E. McKenney" Subject: [PATCH RFC 2/4] hazptrtorture: Add testing of on-stack hazptr_ctx structures Date: Thu, 7 May 2026 09:51:11 -0700 Message-Id: <20260507165113.2039524-2-paulmck@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <5bfe6ac9-432e-43b8-8290-59ca249b0f80@paulmck-laptop> References: <5bfe6ac9-432e-43b8-8290-59ca249b0f80@paulmck-laptop> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit This commit adds a test using on-stack hazptr_ctx structures, in contrast with the per-CPU structures used by the initial test. Signed-off-by: Paul E. McKenney --- kernel/rcu/hazptrtorture.c | 48 +++++++++++++++---- .../rcutorture/configs/hazptr/NOPREEMPT.boot | 1 + 2 files changed, 39 insertions(+), 10 deletions(-) create mode 100644 tools/testing/selftests/rcutorture/configs/hazptr/NOPREEMPT.boot diff --git a/kernel/rcu/hazptrtorture.c b/kernel/rcu/hazptrtorture.c index 1949a8da4f8c9d..1a61d35ade1d9d 100644 --- a/kernel/rcu/hazptrtorture.c +++ b/kernel/rcu/hazptrtorture.c @@ -30,9 +30,10 @@ MODULE_DESCRIPTION("Hazard-pointer module-based torture test facility"); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Paul E. McKenney "); -torture_param(int, irqreader, 1, "Allow hazard-pointer readers from irq handlers"); +// @@@ torture_param(int, irqreader, 1, "Allow hazard-pointer readers from irq handlers"); // @@@ torture_param(int, leakpointer, 0, "Leak pointer dereferences from readers"); torture_param(int, nreaders, -1, "Number of hazard-pointer reader threads"); +// @@@ Does testing CPU hotplug make sense for hazard pointers? torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)"); torture_param(int, onoff_interval, 0, "Time between CPU hotplugs (jiffies), 0=disable"); // @@@ Move the rcu_torture_preempt() function and friends to kernel/torture.c. @@ -194,7 +195,8 @@ struct hazptr_torture_ops { static struct hazptr_torture_ops *cur_ops; /* - * Definitions for hazard-pointer torture testing. + * Definitions for hazard-pointer torture testing using per-CPU hazptr_ctx + * structures. */ static struct hazptr_torture *hazptr_torture_read_lock(struct hazptr_ctx **hcpp) @@ -252,6 +254,29 @@ static struct hazptr_torture_ops hazptr_ops = { .name = "hazptr" }; +/* + * Definitions for hazard-pointer torture testing using on-stack + * hazptr_ctx structures. + */ + +static struct hazptr_torture *hazptr_torture_read_lock_stack(struct hazptr_ctx **hcpp) +{ + struct hazptr_torture *htp; + + htp = (struct hazptr_torture *)hazptr_acquire(*hcpp, (void *)&hazptr_torture_current); + return htp; +} + +static struct hazptr_torture_ops hazptr_stack_ops = { + .init = hazptr_sync_torture_init, + .readlock = hazptr_torture_read_lock_stack, + .read_delay = hazptr_read_delay, + .readunlock = hazptr_torture_read_unlock, + .sync = hazptr_synchronize, + .irq_capable = 1, + .name = "hazptr-stack" +}; + /* * Hazard-pointer torture writer kthread. Repeatedly substitutes a new * structure for that pointed to by hazptr_torture_current, freeing the @@ -337,7 +362,8 @@ hazptr_torture_writer(void *arg) */ static int hazptr_torture_reader(void *arg) { - struct hazptr_ctx *hcp; + struct hazptr_ctx hc; + struct hazptr_ctx *hcp = &hc; struct hazptr_torture *htp; unsigned long lastsleep = jiffies; long myid = (long)arg; @@ -488,13 +514,15 @@ hazptr_torture_print_module_parms(struct hazptr_torture_ops *cur_ops, const char { pr_alert("%s" TORTURE_FLAG "--- %s: nreaders=%d " - "stat_interval=%d verbose=%d " - "shuffle_interval=%d stutter=%d irqreader=%d " - "onoff_interval=%d onoff_holdoff=%d\n", + "onoff_interval=%d onoff_holdoff=%d " + "preempt_duration=%d preempt_interval=%d " + "shuffle_interval=%d shutdown_secs=%d stat_interval=%d stutter=%d " + "verbose=%d\n", torture_type, tag, nrealreaders, - stat_interval, verbose, - shuffle_interval, stutter, irqreader, - onoff_interval, onoff_holdoff); + onoff_interval, onoff_holdoff, + preempt_duration, preempt_interval, + shuffle_interval, shutdown_secs, stat_interval, stutter, + verbose); } // Randomly preempt online CPUs. @@ -570,7 +598,7 @@ static int __init hazptr_torture_init(void) long i; int cpu; int firsterr = 0; - static struct hazptr_torture_ops *torture_ops[] = { &hazptr_ops, }; + static struct hazptr_torture_ops *torture_ops[] = { &hazptr_ops, &hazptr_stack_ops, }; if (!torture_init_begin(torture_type, verbose)) return -EBUSY; diff --git a/tools/testing/selftests/rcutorture/configs/hazptr/NOPREEMPT.boot b/tools/testing/selftests/rcutorture/configs/hazptr/NOPREEMPT.boot new file mode 100644 index 00000000000000..1d09a6446080a1 --- /dev/null +++ b/tools/testing/selftests/rcutorture/configs/hazptr/NOPREEMPT.boot @@ -0,0 +1 @@ +hazptrtorture.torture_type=hazptr-stack -- 2.40.1