From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ed1-f53.google.com (mail-ed1-f53.google.com [209.85.208.53]) (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 10EBB3749F2 for ; Fri, 11 Sep 2026 15:17:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.53 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789139846; cv=none; b=lGSUlNhpIdIheTGQLHgkyCzUc8X8HVSoP4GnxXPXekxVoG4D+RWnBHjn7X9+Xl9euZV8eBal+afzzWdWH5NAR4N8Wpjq/DwwfTXGjJ2HHVe8LE043tBqAXfT6TaGdJKn8P7kZvj+dFasUL2HMVLjhyq4yvhK+4ssFnEvBFYj+08= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789139846; c=relaxed/simple; bh=2JzqsoiLxocAa5D2L3SPzdIZsS+OW1mUD+PJx4LQgiw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Wh3wL783fMX9aVxLx1fJe3IFnHkMx13ZzZvgoJvmsUCO5vthmFmW0wy/uqpYIokEN4BAr7jW0l0xWsoGonbGOOshOmK2WEaaNWlrpqaKeQPNcUE6pCQujPLFNYsVxUotGmRewj3+Ayj1LK9G6NAu3pF1xGkaTFjy0AmN+iiOpdk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com; spf=pass smtp.mailfrom=suse.com; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b=I6RtdCym; arc=none smtp.client-ip=209.85.208.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b="I6RtdCym" Received: by mail-ed1-f53.google.com with SMTP id 4fb4d7f45d1cf-6a173ad7cf4so1595621a12.3 for ; Fri, 11 Sep 2026 08:17:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1789139843; x=1789744643; darn=vger.kernel.org; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:from:to:cc:subject :date:message-id:reply-to:content-type; bh=2JzqsoiLxocAa5D2L3SPzdIZsS+OW1mUD+PJx4LQgiw=; b=I6RtdCymQit8YVXUfVke0ZwgoF+2b4Tc/vK0eZ2VUZDUJChIYtI6CnGF4+IqV5FMy3 LOyeMJAaPO2kxMgLgb1ATDws207sX2VFKoAFTuMzLtypckeKCdP8poCGi+BBj04Lfq+D kG9uHWBdcrp47SkdypV1RxuPCBKHyoJhlalbk3yJG1h39CeiZQW7rqBlpHHhXbIcxNDJ 1CDfNWCv8YLccrEGqj9XLOO7+0cvtgfU4Jl2JwaD/kkPq/DrsUYm+ycsaBjzpikCU2xH OaOTgz7S78hceZxdyxmBLUuED4unG6DduCxil069rY9oJ3424QX13qkDmAkBTb1egp9j UO9Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1789139843; x=1789744643; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=2JzqsoiLxocAa5D2L3SPzdIZsS+OW1mUD+PJx4LQgiw=; b=IUzddS5qP8q9APNaCkOZOejAK9eadhrfz7Vvx7eusGbb95gLhEdP7+FWE4JwN6Rl74 jJ8JbP+WYjNAmxxAgDB+HXIx93EoEqb6teXaFYqLtmfM7b0GntgkR0BfW8rfb0KFXWzy QWzZeMKsj0wvWy3dCkH12Cyo6e6EYnX2LdYuwaFEVg9wTxotSukFLF67LhGbl5nVaYh4 B2esAyzOZIQW9bFjOOAjymTLdZINjqCkQ9/GB8ogDSegzNIGPRklUXddg6n2kkaTuXNQ 61ayveDQJe+FLpIwYBvXyNNDNbBPxBleMl15AV8viC+oPq4hRzSOtaSXPyfCGgEsHl2I NBlA== X-Forwarded-Encrypted: i=1; AKwUvBzmbwBRIuepPCDQE4Jory4RM1USM9xRvjYjAYAncp8NKY1N8nTK6GTku5fj4OjS7XaK7VzhOKXG@vger.kernel.org X-Gm-Message-State: AFuF++kXraVw+To8rh1WttXI1LjCNRm/WFc2qFvnN3sgIvAT8P8DdY4I o3WjtAe07MKKnqTMlI7v62/l+1HehxqAQjEM+xN/K2X1tckbC/sWsN10zq9BcCpVKLM= X-Gm-Gg: AYBFou3GCjjCKyOqbOx5xbwJ4y7B7xpRoLQFO2Ja9xhx95MI1RdbcHxB/at6ViA3tDo K2D1U5AFarfgSRViz+77FYN7Thu3i2u2s2ePupgHe5A+uw3j34G4FrkzS6G6cCeFKiXo7dwHHFr aez+BL0VAYYTGdMaUYC6WtxNhf2NmAM6KpoKtsXzFY5ToOV8o1HacQ7OrEjoK1cnT702qh/4Ywa kqP5qZBry3ScS7JcGvLlFQ1qV1aMcXy8i/sdXmUIUcH962+p6usQid5z8KxQJQvOTAKb72t2cud J8m6Mfe0V5XPltOHeHk3vQA24zyrmh0OI0F9coEOa8ubnb6zuTdhkEsg0aFAq3Wr9JIyqGrMiOz EOQVj7FxHubsvAhrPUjSDnFWx4FKdN8/SiiZQjRZHxnyyB8f0d3mbpeXmjMf1EJpjMTXigtsHy+ hPfnBUmP3oDNYvqVleFWMf9cWX03jCGS0tkTPHs23+Z/8O6hJH/orecE4Gcv1wwwbIPAJzXZmxk g== X-Received: by 2002:a17:906:6a03:b0:c29:45ce:85ad with SMTP id a640c23a62f3a-c29667f24c6mr225571866b.1.1789139843199; Fri, 11 Sep 2026 08:17:23 -0700 (PDT) Received: from localhost.localdomain ([2001:af0:8000:1409:193:86:92:181]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-c2966026e2esm93138666b.19.2026.09.11.08.17.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 11 Sep 2026 08:17:22 -0700 (PDT) Date: Fri, 11 Sep 2026 17:17:20 +0200 From: Michal =?utf-8?Q?Koutn=C3=BD?= To: linuszeng@tencent.com Cc: Johannes Weiner , Michal Hocko , Roman Gushchin , Shakeel Butt , Muchun Song , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Maarten Lankhorst , Maxime Ripard , Natalie Vock , Tejun Heo , Oscar Salvador , Jingxiang Zeng , Michal Hocko , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org Subject: Re: [PATCH v2 0/3] mm: page_counter: move hierarchical protection out of struct page_counter Message-ID: References: <20260909-descriptive-name-v2-0-d7dd7c099049@tencent.com> Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="ozrropszbqjorccy" Content-Disposition: inline In-Reply-To: <20260909-descriptive-name-v2-0-d7dd7c099049@tencent.com> --ozrropszbqjorccy Content-Type: text/plain; protected-headers=v1; charset=us-ascii Content-Disposition: inline Subject: Re: [PATCH v2 0/3] mm: page_counter: move hierarchical protection out of struct page_counter MIME-Version: 1.0 Hi. On Wed, Sep 09, 2026 at 05:44:18PM +0800, linuszeng via B4 Relay wrote: > No functional change is intended: protection semantics and the cgroup > v1/v2 behaviour are preserved. It is not clear from the description what is the intention then :-) Do you have any measurements that the reduced cache footprint changes performance for setups without protection? And what is the positive impact on protected scenarios where the counters are in (possibly) different cacheline and one indirection further? Thanks, Michal --ozrropszbqjorccy Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iJEEABYKADkWIQRCE24Fn/AcRjnLivR+PQLnlNv4CAUCaqQbfBsUgAAAAAAEAA5t YW51MiwyLjUrMS4xMiwyLDIACgkQfj0C55Tb+AjHdwEA9eabDSoks6Xn+ni3bc0I AP32Ul+BBWTmz5HMyoTjovoA/2JJSh5lKBEsuu0fwEMrZGzX9XiTI5mG6CHzszPG ztkH =VS/g -----END PGP SIGNATURE----- --ozrropszbqjorccy--