From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj2-f13.google.com (mail-pj2-f13.google.com [74.125.227.141]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9CC5834D91F for ; Sat, 26 Sep 2026 15:51:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.227.141 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790437916; cv=none; b=KXahGFe8cEmUCLIwIA5sbwvI/cmURNRrjMjp0ye/MhBlyHbm7Z3OZ6atlB8/pOksKgOapzCYfJqWh2Jh4vrrtm/zfOPbby/Xb3+rulQjLkfa2MztK1d0E9TPv+I2z3a3iZ6VZ4lNeoR1+wcrB7WgsUFTICwV5ElJzuizF4ecUM4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790437916; c=relaxed/simple; bh=b+i0D9X2F2S0Np++TT2ia1qmbBpvCbKPzmMUSt0WLg4=; h=Content-Type:Date:Message-Id:From:To:Cc:Subject:In-Reply-To: References:MIME-Version; b=iH5rn8Y+dBzKdzvyzfmbgUQOjr4TxLWLxwq5kJp58QA5Lj7wjvoQBdT5qGZifqHx43UV13I1UCjX8vMgcqhoBcsEGdhO/cbsrHM5scla8c3039GWR6PxUijUrwUxawv4d/VzVexfVzRavpoLDhUz56H4h+//GeO/e8zrS1WYkI4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=TMkCgja8; arc=none smtp.client-ip=74.125.227.141 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="TMkCgja8" Received: by mail-pj2-f13.google.com with SMTP id 98e67ed59e1d1-396ccb65437so1034742a91.3 for ; Sat, 26 Sep 2026 08:51:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1790437915; x=1791042715; darn=vger.kernel.org; h=mime-version:content-transfer-encoding:references:in-reply-to :subject:cc:to:from:message-id:date:content-type:from:to:cc:subject :date:message-id:reply-to:content-type; bh=KsnSXE0hO86vtMaQL0ebt/kiteifSy5eNA8IBCdtnCM=; b=TMkCgja82MooF0CfUYCFRU1BDP+8aFX2F7a/RsWAZB1xD59VFGRd9khazPNrw82GiO K2Jd9iHN2ZGyLLHiuVd8hAByPoyzp9RkDufpnhY/2T0JJcES07k2ueWvFgYNrF+U2jAW 8XvPgUDjIGktXvs5WbkO6ZN4V3wztHV1LjuVi9FYc62jPATxNgBQ8IHpa6XB5hM707np AsmiznR6vUZU4YKpAFqCpjx2m21wywDG+tTDa38YF7OQktH9N73GYRQMzcTQ068FDgyg ulowgrs4XQHvAeixsvG1MZVXToyx4gV5UBowQUHSCh5kl5aFFQba0DOmami5CHXUjlvP w/7A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1790437915; x=1791042715; h=mime-version:content-transfer-encoding:references:in-reply-to :subject:cc:to:from:message-id:date:content-type:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=KsnSXE0hO86vtMaQL0ebt/kiteifSy5eNA8IBCdtnCM=; b=u8jYdZqxL8ZgMjWbnkXjvgApXcs/o9/eLkdspEZqO83fftZ6eB2o+JE2dHNcOwuqeX rOjJiEmk5ArHGDFWEHKji+2TKz5e2yaibzX5wCa11XO6Rm07Cde/5M5DXGJSgJYkz7cM mAUdrcUaSzwTtVqh/zIYAoDugMwEkzK2vgenw7fZ169WGNWseFki++wIsQVrTv5QY4DZ aqk2ErEx+3ry/vBQgkYMN3/8DFhme6IFJs17JmAyFN6iydy0Anqvi/wKmLortSVaS5Fc OWhDIr7ZBssKcnQQ4sE3XDH/TOutMRXNhDSGgDz1mWH5DQPwIpwf3KW8XK3BGfRsxIhd +9vA== X-Forwarded-Encrypted: i=1; AKwUvBxLeJk6JKDr8rjeOHe1iczY6U/Pczs6KNxYkQtqRRn5f3E46YNHuS73e23oCYDotOTBf+M=@vger.kernel.org X-Gm-Message-State: AFq9FYI1RtR80BmueNO6DSKo2BcdX1U2UJAur5Rmn3ecEXhH5/rZxb2d K5StpZniqmQ7JWh0Ua0+hG1flSCsEafnVGhMMogJs9XVKfCPp/7XTYU3 X-Gm-Gg: AYBFou2ieNCKnhnBXJvgwE07mDQ2WCJ9e9iSQx25UqA7svk6Dxyo/voxpRg4YcMDdFz oAJXT4fvSplL4agDPhOJmW86mnBjoEUEwPuokT1GtRA00BH6HIMyMS82dbW2jDWjdG0uvpn3Ji9 yg6A3yEBjGluXQ2uvUlwqJOUti7WLP53KQlQhOOFzFuKFWaIvJrlP0Ta7O+gAk+yN3vDJbVZlz/ JaaBL9LB5Djg8HoRIjOk0t8AVcuL4VxlCbJH+OI+NRLsIfk9nVizpf8Xcay6+9rjR5dlbCMZUaX is46nCHCAaPZ2gmkUo/NzTMvzZIq9wCeatcc3kVE/QYaYDJsfZCKPT/NqieFf+iXYaP7QCnwwlO XsQLVDE6ksIp+oi16Wir7yGecknyluSlNvWyO+1T8N38d/U1lknoTaXGqwBjYsle6CTGZ/iR7r0 BzjLxF81PpGuRY+fHmwnukFxj8awPgh9pWgcUsGo4JQ2M7D+2g6Ws19HLxQxuk/aBnywHXjC9zP QRToFrptYCgV4bDJFqHmBtEoiSK7RcjI/+GDTx3PV9LY1IcjEA8fvw/2Tj+q5Jbhu8Hg7gcHzE1 yKHm X-Received: by 2002:a17:90b:4b12:b0:39e:6c6a:4b78 with SMTP id 98e67ed59e1d1-3a098e43c20mr8101152a91.66.1790437914882; Sat, 26 Sep 2026 08:51:54 -0700 (PDT) Received: from localhost ([153.61.198.248]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-3a0974ec5dfsm16527115a91.3.2026.09.26.08.51.52 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 26 Sep 2026 08:51:53 -0700 (PDT) Content-Type: text/plain; charset=UTF-8 Date: Sat, 26 Sep 2026 15:51:52 +0000 Message-Id: From: "Alexei Starovoitov" To: "Eduard Zingerman" , , Cc: , , , , Subject: Re: [PATCH bpf-next 02/36] bpf: summarize may write stack slots in insn_aux_data In-Reply-To: <20260926-scev-minimal-rebase-v1-2-c8e5ab5ba79f@gmail.com> References: <20260926-scev-minimal-rebase-v1-0-c8e5ab5ba79f@gmail.com> <20260926-scev-minimal-rebase-v1-2-c8e5ab5ba79f@gmail.com> X-Mailer: mkdraft (claude review draft; edit before sending) Content-Transfer-Encoding: 8bit Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Sat, Sep 26, 2026 at 07:20 AM Eduard Zingerman wrote: > @@ -662,6 +662,11 @@ struct bpf_insn_aux_data { > }; > struct btf_struct_meta *kptr_struct_meta; > u64 map_key_state; /* constant (32 bit) key tracking for maps */ > + /* > + * Per-instruction summary of stack slots in the current frame > + * that this instruction may write to. > + */ > + DECLARE_BITMAP(may_write_mask, MAX_BPF_STACK_SLOTS); That's 32 bytes per insn and the next patch adds 32 more, for every prog whether it has loops or not. FM_MAY_WRITE in patch 1 makes every frame_masks a third bigger too. commit 481ceda77aeb sized the liveness masks by the stack the frame uses to avoid exactly that. bpf_may_write_mask() is the only accessor. Can the summary stay in liveness.c, as wide as the subprog's stack, and only for insns with scc != 0 ?