From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 DFA68188CB5; Mon, 19 Aug 2024 19:35:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724096117; cv=none; b=XWOH8NvimagkOZioEqWmixHQz98i4XOzNpMy7G4SV2cgwd0tRY7taCIi/IzIomD9ezZd5u9tStr5WeXH4xEwDVk1eW01vyiKERs9i60sxxMfQ+WsxmP7wnmPidT3BTeHO37fTazXh4EOTlxt6Mdnl5WJ2fvLV0s7gRXwqNNnP7I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724096117; c=relaxed/simple; bh=Q+bTT1LIdx6rvUFMUtXwA6/VxsX+IhQMYF6gDPYwzqw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Hq+lseo9UN1IYJUY/3xn22eXDztKltlojXRV4JhCbqrMzbnT9u9qUGmHQ1IFVdY25ulFfYC7ToCSDjUKdaFwVz66YcUnTWV9C67jsdvujpJG1hf+TFL9LDZMkiQfr9ZXKx3aI7fTvB99Dwfi5nmoqJEEBAlSX9srdDsoRmCtr8M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=S+ehbQTT; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="S+ehbQTT" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=GgkSbPAh5KOwEoij59vzgPrDRTBo+einBkTJg8LJEK4=; b=S+ehbQTTfQwUW7uPpk8GapUl5B UO27g31htpfVF8q0tyK5h/zlnt2RYj7JCfRQUYM5OiyXwoEUmOge9o1JcD96tqAWweRBzatGnfKxH VN/YgyIk0y2cYf29wKLGiXYWuCpUb17YjC7ggGWRTyeUu+EDzYPxRDWbzKwAhXqpv3nv5WqGX5ESc DbrtlZEny2y0WZ/yHSwFo7U5w3IQYBc0fgxUWBJB7RNJp8CD5J43eaMuxjscMGXg5IP1nbIn0wiOk W7XM61Oz0TFCyF49R96gNVaj0RkF/D9/rMcqbxN7Pn8Fhj8yJKD0g1tNyjpwkBvX+mln0qY+xZi8N yc+2QiZQ==; Received: from willy by casper.infradead.org with local (Exim 4.97.1 #2 (Red Hat Linux)) id 1sg89N-000000076SA-4BDT; Mon, 19 Aug 2024 19:34:46 +0000 Date: Mon, 19 Aug 2024 20:34:45 +0100 From: Matthew Wilcox To: Suren Baghdasaryan Cc: akpm@linux-foundation.org, kent.overstreet@linux.dev, corbet@lwn.net, arnd@arndb.de, mcgrof@kernel.org, rppt@kernel.org, paulmck@kernel.org, thuth@redhat.com, tglx@linutronix.de, bp@alien8.de, xiongwei.song@windriver.com, ardb@kernel.org, david@redhat.com, vbabka@suse.cz, mhocko@suse.com, hannes@cmpxchg.org, roman.gushchin@linux.dev, dave@stgolabs.net, liam.howlett@oracle.com, pasha.tatashin@soleen.com, souravpanda@google.com, keescook@chromium.org, dennis@kernel.org, jhubbard@nvidia.com, yuzhao@google.com, vvvvvv@google.com, rostedt@goodmis.org, iamjoonsoo.kim@lge.com, rientjes@google.com, minchan@google.com, kaleshsingh@google.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-modules@vger.kernel.org, kernel-team@android.com Subject: Re: [PATCH 5/5] alloc_tag: config to store page allocation tag refs in page flags Message-ID: References: <20240819151512.2363698-1-surenb@google.com> <20240819151512.2363698-6-surenb@google.com> Precedence: bulk X-Mailing-List: linux-arch@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240819151512.2363698-6-surenb@google.com> On Mon, Aug 19, 2024 at 08:15:11AM -0700, Suren Baghdasaryan wrote: > @@ -91,7 +97,7 @@ > #endif > > #if ZONES_WIDTH + LRU_GEN_WIDTH + SECTIONS_WIDTH + NODES_WIDTH + \ > - KASAN_TAG_WIDTH + LAST_CPUPID_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS > + KASAN_TAG_WIDTH + ALLOC_TAG_REF_WIDTH + LAST_CPUPID_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS > #define LAST_CPUPID_WIDTH LAST_CPUPID_SHIFT > #else > #define LAST_CPUPID_WIDTH 0 So if ALLOC_TAG_REF_WIDTH is big enough, it's going to force last_cpupid into struct page. That will misalign struct page and disable HVO -- with no warning!