From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from SHSQR01.spreadtrum.com (mx1.unisoc.com [222.66.158.135]) (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 698863DFC81 for ; Thu, 14 May 2026 09:08:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=222.66.158.135 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778749710; cv=none; b=JmXoPKlEoAZW3k4Q5/ezuZ/VwClKioFsphLmZM+NX6j/9K7H2OF2MTY66PKAc5CLRyUnBdOTtRt3JBa3f2mLlsAz6yb6A9Ks3+WWP/8EsBji3cG04ZuX1bfH4UQLwb0KTAkZjYSZiuvp95CFGLQigEr97629hza93Kmr/OP2qYc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778749710; c=relaxed/simple; bh=uAnCUNpwi/P3Iv3BzUDoBjorhq+Vxsjug8h01Dt4w+8=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=UWcxLEuGIoVBxsqEObmVf8SiqLRYYkgFneOU1qOuQuy25qHVUorPLq5/tQlSUwb2+zHPhnIk2UtyxXiCMmotE7CTezkbjv+LhGTty4f/BUf48Zh4t8DruyhrFu57yfHs311h5zEAkz5//ml1gJ/qTUFqeidy1ERhydCf7KriLAU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=unisoc.com; spf=pass smtp.mailfrom=unisoc.com; dkim=pass (2048-bit key) header.d=unisoc.com header.i=@unisoc.com header.b=BASSahcr; arc=none smtp.client-ip=222.66.158.135 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=unisoc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=unisoc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=unisoc.com header.i=@unisoc.com header.b="BASSahcr" Received: from dlp.unisoc.com ([10.29.3.86]) by SHSQR01.spreadtrum.com with ESMTP id 64E96Efc012294; Thu, 14 May 2026 17:06:14 +0800 (+08) (envelope-from Yi.Sun@unisoc.com) Received: from SHDLP.spreadtrum.com (BJMBX02.spreadtrum.com [10.0.64.8]) by dlp.unisoc.com (SkyGuard) with ESMTPS id 4gGPVb65rnz2Msdqx; Thu, 14 May 2026 17:02:47 +0800 (CST) Received: from localhost.localdomain (10.5.32.15) by BJMBX02.spreadtrum.com (10.0.64.8) with Microsoft SMTP Server (TLS) id 15.0.1497.48; Thu, 14 May 2026 17:06:11 +0800 From: Yi Sun To: , CC: , , , , Subject: [PATCH v3 2/2] lib: bitmap: reduce the number of goto again in bitmap_find_next_zero_area_off() Date: Thu, 14 May 2026 17:06:07 +0800 Message-ID: <20260514090607.231387-3-yi.sun@unisoc.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260514090607.231387-1-yi.sun@unisoc.com> References: <20260514090607.231387-1-yi.sun@unisoc.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: SHCAS03.spreadtrum.com (10.0.1.207) To BJMBX02.spreadtrum.com (10.0.64.8) X-MAIL:SHSQR01.spreadtrum.com 64E96Efc012294 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=unisoc.com; s=default; t=1778749590; bh=ANLwQX9tCHeq2zTiX4PeFSwE509VuBzyXZ/74Js+d0Y=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=BASSahcrzgieiMQbARWq58iHrD8/8WcsNz4tIQ8Zo0tH6mh/NFK9HR/HyOWh3odxn gNG6KvxiR36vVeWfIj78d5fiNy2khbWrNYYjpI5MY5pW+COg/0aBZKsj57dJMgbef1 O0RR1kEkSb4Z90bQLB1y2ErSzpdzlr9ucny0RAnaS6EKRWZ4Qbyrot1N8jJz5Rxslq 3B2PZzbJIqDDB1VlTJ7oRGPneBP7nAf59jIbPpyCEIzjJH+NVngJDTbmkgljRAwnYK fOrOTiaoyd0+13KdMQGAhd8TnIZCiUD33FJFEdulMMDdw+QpBHHSe3u+1joJdCEzNR lzgheLH/vov0A== Finding a contiguous free region in a highly fragmented bitmap is not easy and may require many repeated attempts. Therefore, find_next_bit(map, end, index) is not the optimal choice. This is because there may be multiple scattered free regions within the range [index, end) and none of them will meet the length requirement of @nr. Instead, it's sufficient to directly find the last bit within the range [index, end), thus reducing unnecessary "goto again" calls. Signed-off-by: Yi Sun --- lib/bitmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/bitmap.c b/lib/bitmap.c index b9bfa157e095..9b589643f72a 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -442,7 +442,7 @@ unsigned long bitmap_find_next_zero_area_off(unsigned long *map, end = index + nr; if (end > size) return end; - i = find_next_bit(map, end, index); + i = find_last_bit_from(map, end, index); if (i < end) { start = i + 1; goto again; -- 2.34.1