From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f175.google.com (mail-pl1-f175.google.com [209.85.214.175]) (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 D6DC52E3B0D for ; Fri, 7 Nov 2025 22:04:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.175 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762553049; cv=none; b=MbtES3kWthmQP82euoVWZipQS3RwHk+3L8oA01bJt9btHzS0wI166fSp5Rv/BsWexlMzOfRHQms3ns36r5t5mcxzwd5w1eCRHSvAPHZpbbtLx/D81XdTYjv3MaLyyB28hzWJkMWSsf9+zIRYjMQD5tZhNoFhN9PCfHXfvfB/QOM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762553049; c=relaxed/simple; bh=rH5NWi3glmpfoUsyrWFIS1fb1JBwFyE3VlN/OmM4ilY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=d+7k3/vbnt9k8nelW58wXtUz+4qw80cqOPz4QPrCyhdj1R3p4lMFt2o3AR1Wuu6nViAFZX6fJBD6u7ZcSpMN75Jfoc4sSBPK0IWIk4l9gypLcs7GT+cxXM5kOd5Qa/XZyb5M7zv2galp2PZDsxd4XmDGFVg7koqUBRmlAR3m/U4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=3qnRij6a; arc=none smtp.client-ip=209.85.214.175 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="3qnRij6a" Received: by mail-pl1-f175.google.com with SMTP id d9443c01a7336-2959197b68eso19255ad.1 for ; Fri, 07 Nov 2025 14:04:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1762553047; x=1763157847; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=cRweDbYCqtyY9POZrBGfSKktHIdUt3/r/qQ6F0Pf6Fc=; b=3qnRij6aVrqTjfXWzxAfEaSRm/mVfPm1PHYD0o4tb47ywS6YOFN02cOs0+wl+/HEbz bdeXUvuSOfZDSUJKJzHpeBsIZmgLB465rRbSsYiZQSzB+TW5s4D2vgPL+Tc2uBd7TUI2 WGvDc0ysMOtLu+36XBI0S0Eyd70aVYhq9BmSkF0TF7EGdK9oz/X3sIFCn5EbXqoNfhCo S9K95ZLgMyFeJhe7Shkydso99fAWE0IArfvBW/zCxZiYSAt7hUCtTgIc8bvL7MCTcgRE IfOjAp3j3U0KUdHXWHfBfBt2RM/wddejwlaY1YhvjV0p71AijbYkzIbALuo+751g1qCL GMaw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1762553047; x=1763157847; h=in-reply-to:content-disposition: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; bh=cRweDbYCqtyY9POZrBGfSKktHIdUt3/r/qQ6F0Pf6Fc=; b=RFa69n9biF9+tZyAFYo0TBp2Etd0Ny6rnF3S9EtHZimwaisB/sZhPve+JWm4Uz4W5a mqeXEptog1hZxmQRW7NB5P7mWTR55HG8pzMVdafhoeGsR0us+kY9ww1X0wD1cGg46BFx GPczwN7/uueqq7uOtVBcYKR+yAByG7ZoOgwuSTLR/yXbQ4b5EbFV6rEiosDg3oPS1fAW CsZFjuhhTEU+KKuNim8XU+uMn3w8aunFIEWAXaOCdxe9/QRPFXWvZjx3MdLwR9en/9yf 5G0RdIg4oTzeeWolpoY0dcVcd6OIWvP5mQxQxDnwUUkR2oAkEeIV9UQoZkSUhK3JuvB9 Neog== X-Forwarded-Encrypted: i=1; AJvYcCW0ZKheJZQU4BGCBV5oLkjzEB6ztVBXJvbmAp9M1FIxkfPUlpGPm7C7czPywm7qb3pOUIrWum7OcFVfc6w=@vger.kernel.org X-Gm-Message-State: AOJu0YwKAqyaYBbFzG1NLwY7rWYvS5cYaiZXBRkqJ/GTbgflkpdCAD6P P+4Bo9B9LCcGCjuRStdTcpH7W+Bf8VAP/r2Vvc4Zps0muvI62arn50WGM2zmP/4Q8Q== X-Gm-Gg: ASbGncsyQw8cqmFNRJOOqoR3wUwGYjHD1iFT3g+Wiq/s98rX9hMIlQW+vgBqkAF/SAQ lYdCgxplWavpOtGG2IDBKIpjUyuj9jOk6SaeCh2bCu8Qb3c8TKVMvy6zYGftRIEgXBCghC0DdBD 1/1CvRYuml9W6cbqCJn/BMlmEt7lkMHES9Whx7/OHtGgFONJk+UZdrDGc7uEkeapHMHVbZ3p+D0 p1FLYcwb3bO6Atol0i/dPgFvTNEQ5lTe0fM1jJm2AVMyHApNdMZjtAPKSTU4FsN1kCEdJAVmPmZ GjnBvP9/vixH7sqH6jREfgjnp74dJTzPv6eC3+rwbkC9qHPPSrbp2s7JHyVrWDXm5747JbaIKw2 MY2lLptbsoZwhXyQqqAcif4mc/01h+j9+d8yoGvazwkLuS80LsLOu4RsA4HBJ+JURefh256X1FO pX2ED4qgCoVvGJUHq6ULBtp7VanFyyvn+6PNeKOn2nDuA74Wu0VpjWiB4MeC7ym+AUAldEZBweG UTPRKHGxm14KOZ3BbN04lQk9Q== X-Google-Smtp-Source: AGHT+IFv2mkQSlcQS4PXvqaG+xeTcSDoHEqmlso5Xj5Eq3iLbnE3+0IuZGmN3O/yv/DGH1pt27g8qg== X-Received: by 2002:a17:902:db09:b0:290:be4a:40d2 with SMTP id d9443c01a7336-297e7c0146cmr310255ad.13.1762553046909; Fri, 07 Nov 2025 14:04:06 -0800 (PST) Received: from google.com (116.241.118.34.bc.googleusercontent.com. [34.118.241.116]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-341d0b427e1sm3437566a91.2.2025.11.07.14.04.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 07 Nov 2025 14:04:05 -0800 (PST) Date: Fri, 7 Nov 2025 22:04:00 +0000 From: Carlos Llamas To: Alice Ryhl Cc: Greg Kroah-Hartman , Yury Norov , Arve =?iso-8859-1?B?SGr4bm5lduVn?= , Todd Kjos , Martijn Coenen , Joel Fernandes , Christian Brauner , Suren Baghdasaryan , Burak Emir , Miguel Ojeda , Boqun Feng , Gary Guo , =?iso-8859-1?Q?Bj=F6rn?= Roy Baron , Benno Lossin , Andreas Hindborg , Trevor Gross , Danilo Krummrich , rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 5/5] rust_binder: use bitmap for allocation of handles Message-ID: References: <20251028-binder-bitmap-v3-0-32822d4b3207@google.com> <20251028-binder-bitmap-v3-5-32822d4b3207@google.com> Precedence: bulk X-Mailing-List: linux-kernel@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: <20251028-binder-bitmap-v3-5-32822d4b3207@google.com> On Tue, Oct 28, 2025 at 10:55:18AM +0000, Alice Ryhl wrote: > To find an unused Binder handle, Rust Binder currently iterates the > red/black tree from the beginning until it finds a gap in the keys. This > is extremely slow. > > To improve the performance, add a bitmap that keeps track of which > indices are actually in use. This allows us to quickly find an unused > key in the red/black tree. > > This logic matches the approach used by C Binder. It was chosen > partially because it's the most memory efficient solution. > > Reviewed-by: Burak Emir > Signed-off-by: Alice Ryhl > --- LGTM, Acked-by: Carlos Llamas