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 1380E3DBD55; Wed, 4 Mar 2026 22:01:42 +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=1772661703; cv=none; b=HIAaQXI6fn6Gqbx+r/8bG4moeVWgpPe3cAZ02cty1TnESQZUEjWFqqmNPOS7gYl+zhpM9Sq8LF+5v4vAzprmidB8Xcg7xMTGs1vk8S7kGiC1p1f2z3YqMqjjh5T8jV1MLl/kPrMk6rAUUx/ik/gHFXl+QYaeJVpbIITWkjw6+EE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772661703; c=relaxed/simple; bh=lBuYIYG8FaGBLIEQkB3q9e5c1sJh26dfObh3wsQlRa0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=O94C89ec/X98RnlzJ5aRVT+XjIXHhkrzOR5vn/OAGzGenFoA7JBn3ii6UzA+f1p8GZLLUp0EEYj5SULTKDiMqoYYN1RFbC9JtPViQwKy0042v/E19DrfhUUbVZT6QxeP2gvXzPOEWfGklSAuCO5g/tavmjmVtaRY7bnpvwnad3Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VYunSZFW; 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="VYunSZFW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 803C6C4CEF7; Wed, 4 Mar 2026 22:01:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772661702; bh=lBuYIYG8FaGBLIEQkB3q9e5c1sJh26dfObh3wsQlRa0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VYunSZFWwHnSZUBtimlpHDp+hpuQVOd+rTrYFliJE0b7hXLy/+jx/RRbQ6S91jlpj ZnfBO4r/PDXJ7s67XsdIfamCwrsBlJOhaYGzLMzd3Qv3TAVsBdTRyxa8uo/z08hlTP 7jd7U+SSzsWswMU/7xJ/kCaDhwGeJEx56C1PztKtbi8PvgVOpTDHifKwXi4Gk6lR6O oGfoLpB6NOJ4pH2Z0ENA6nWl3V6Fa9ICWQzl47UM+KZ/lw196DcMm1ofr42AVHxlDm nL/OuGhXeogdgQdeapBZrIXn8BWUVxZhM4aUhXAP3nzZK4xo/OWPUUS6jCP2uDnnT6 4Nc2bIFsxFRbA== From: Tejun Heo To: linux-kernel@vger.kernel.org, sched-ext@lists.linux.dev Cc: void@manifault.com, arighi@nvidia.com, changwoo@igalia.com, emil@etsalapatis.com, Tejun Heo Subject: [PATCH 21/34] sched_ext: When calling ops.dispatch() @prev must be on the same scx_sched Date: Wed, 4 Mar 2026 12:01:06 -1000 Message-ID: <20260304220119.4095551-22-tj@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260304220119.4095551-1-tj@kernel.org> References: <20260304220119.4095551-1-tj@kernel.org> Precedence: bulk X-Mailing-List: sched-ext@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The @prev parameter passed into ops.dispatch() is expected to be on the same sched. Passing in @prev which isn't on the sched can spuriously trigger failures that can kill the scheduler. Pass in @prev iff it's on the same sched. Signed-off-by: Tejun Heo --- kernel/sched/ext.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index 0082919e2e8f..1570b6a8158c 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -2392,9 +2392,10 @@ static bool scx_dispatch_sched(struct scx_sched *sch, struct rq *rq, struct task_struct *prev) { struct scx_dsp_ctx *dspc = this_cpu_ptr(scx_dsp_ctx); - bool prev_on_scx = prev->sched_class == &ext_sched_class; int nr_loops = SCX_DSP_MAX_LOOPS; s32 cpu = cpu_of(rq); + bool prev_on_sch = (prev->sched_class == &ext_sched_class) && + scx_task_on_sched(sch, prev); if (consume_global_dsq(sch, rq)) return true; @@ -2418,7 +2419,7 @@ static bool scx_dispatch_sched(struct scx_sched *sch, struct rq *rq, dspc->nr_tasks = 0; SCX_CALL_OP(sch, SCX_KF_DISPATCH, dispatch, rq, cpu, - prev_on_scx ? prev : NULL); + prev_on_sch ? prev : NULL); flush_dispatch_buf(sch, rq); -- 2.53.0