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 91D554A18 for ; Wed, 25 Sep 2024 00:06:28 +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=1727222788; cv=none; b=kvxheBwblGeErjWrzDi3og9jlB34zQHhkKzRlj4+ApgSflCJli00ioAZHt7QohrqjqkDnb41piW1OI9zMzhpD7GUT+l+7L6KmtzGfWzQqCvityhLc7fqhIGbGZ0ZpWxtmLneGXrjK0Svmp0FAFumbPsBoEdHAxQObXyd9SxNtAk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727222788; c=relaxed/simple; bh=zcUWpDMdMty+C5ghXKqwkj7R0AZXZqexFFnhFavlOGs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=k0fGXG1ZvpeXBEi5MhZkDLT/85eUQSDUBTvP5/BgAr9CCQAfnwC4OWuhLpyiGc9QZmIZkiS4RfzoZ7UH5U98Eoa+fjlqsJMgfqpnXIhoOZkDVEwJhxrf/ZiCw8wfwT7WZdKQninsn7KkGadNCzYTSKNpLzD3zdtPTmCCc3FCCPE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mT/3ya8K; 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="mT/3ya8K" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E2504C4CEC4; Wed, 25 Sep 2024 00:06:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1727222788; bh=zcUWpDMdMty+C5ghXKqwkj7R0AZXZqexFFnhFavlOGs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mT/3ya8KWywMfuavlzEO/YIsINvppTd5cE+nBZbeH81fYbea+UQuqSpRdZID72JiT fZfOzl59VDN89UgeIkGYZczXWKWl0XdfNin50bTqZTDQLSbCHjLIDLek14pmTKhn5N G4GFevUa7l+TMwWkzhal0f9VvdNVlHievReNp1E03HQax7xAzuE/Hn2JkOUPRf/xUU 4HPUh7WrWcBFKQGgWVsj4lxRW5ObU56c8bDYL+X54+8OJTRTUAyRVPza5AvVYIsL9y dMR4V8QVigZLMiBaORFngMze5T92KiBPlUYQbqbR0cG06plXp5jJvTxCFZ3Al9cIna bxxATQMohgw5Q== From: Tejun Heo To: void@manifault.com Cc: kernel-team@meta.com, linux-kernel@vger.kernel.org, sched-ext@meta.com, Tejun Heo Subject: [PATCH 2/5] sched_ext: Allow only user DSQs for scx_bpf_consume(), scx_bpf_dsq_nr_queued() and bpf_iter_scx_dsq_new() Date: Tue, 24 Sep 2024 14:06:04 -1000 Message-ID: <20240925000622.1972325-3-tj@kernel.org> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240925000622.1972325-1-tj@kernel.org> References: <20240925000622.1972325-1-tj@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit SCX_DSQ_GLOBAL is special in that it can't be used as a priority queue and is consumed implicitly, but all BPF DSQ related kfuncs could be used on it. SCX_DSQ_GLOBAL will be split per-node for scalability and those operations won't make sense anymore. Disallow SCX_DSQ_GLOBAL on scx_bpf_consume(), scx_bpf_dsq_nr_queued() and bpf_iter_scx_dsq_new(). This means that SCX_DSQ_GLOBAL can only be used as a dispatch target from BPF schedulers. With scx_flatcg, which was using SCX_DSQ_GLOBAL as the fallback DSQ, updated, this shouldn't affect any schedulers. This leaves find_dsq_for_dispatch() the only user of find_non_local_dsq(). Open code and remove find_non_local_dsq(). Signed-off-by: tejun heo --- kernel/sched/ext.c | 22 ++++++++-------------- 1 file changed, 8 insertions(+), 14 deletions(-) diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index d74d1fe06999..ed2b914c42d1 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -1808,16 +1808,6 @@ static struct scx_dispatch_q *find_user_dsq(u64 dsq_id) return rhashtable_lookup_fast(&dsq_hash, &dsq_id, dsq_hash_params); } -static struct scx_dispatch_q *find_non_local_dsq(u64 dsq_id) -{ - lockdep_assert(rcu_read_lock_any_held()); - - if (dsq_id == SCX_DSQ_GLOBAL) - return &scx_dsq_global; - else - return find_user_dsq(dsq_id); -} - static struct scx_dispatch_q *find_dsq_for_dispatch(struct rq *rq, u64 dsq_id, struct task_struct *p) { @@ -1835,7 +1825,11 @@ static struct scx_dispatch_q *find_dsq_for_dispatch(struct rq *rq, u64 dsq_id, return &cpu_rq(cpu)->scx.local_dsq; } - dsq = find_non_local_dsq(dsq_id); + if (dsq_id == SCX_DSQ_GLOBAL) + dsq = &scx_dsq_global; + else + dsq = find_user_dsq(dsq_id); + if (unlikely(!dsq)) { scx_ops_error("non-existent DSQ 0x%llx for %s[%d]", dsq_id, p->comm, p->pid); @@ -6176,7 +6170,7 @@ __bpf_kfunc bool scx_bpf_consume(u64 dsq_id) flush_dispatch_buf(dspc->rq); - dsq = find_non_local_dsq(dsq_id); + dsq = find_user_dsq(dsq_id); if (unlikely(!dsq)) { scx_ops_error("invalid DSQ ID 0x%016llx", dsq_id); return false; @@ -6497,7 +6491,7 @@ __bpf_kfunc s32 scx_bpf_dsq_nr_queued(u64 dsq_id) goto out; } } else { - dsq = find_non_local_dsq(dsq_id); + dsq = find_user_dsq(dsq_id); if (dsq) { ret = READ_ONCE(dsq->nr); goto out; @@ -6546,7 +6540,7 @@ __bpf_kfunc int bpf_iter_scx_dsq_new(struct bpf_iter_scx_dsq *it, u64 dsq_id, if (flags & ~__SCX_DSQ_ITER_USER_FLAGS) return -EINVAL; - kit->dsq = find_non_local_dsq(dsq_id); + kit->dsq = find_user_dsq(dsq_id); if (!kit->dsq) return -ENOENT; -- 2.46.0