From nobody Tue Dec 23 10:21:14 2025 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 BDB7614601F; Thu, 9 May 2024 02:41:27 +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=1715222489; cv=none; b=fvnXqJAgQfbas+wayOm+oLQz6kemIGwc51iYGdTObawT/AF8WkPxvKpJ9rVFUPBm6k6uHGNpGYY7gDcxgmgwVZ2sSblhjGbYneo2feUArHmpJSoHhYnOkkBT31/zt6tXf+QSOX7Guk77ZYbD43CbSsfrASSKPlFWbmzi9myKw+o= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715222489; c=relaxed/simple; bh=yMMIUz7DubXFQXYpZ3HCVv1OQrz7GVWdZJEPrbTdrZU=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=kmJNBouEQqkZaZ/Uyz5xIwVdqbccj6bkukFaiWbB0NVZLddlaM0/rCPvrcuCsVIKplktL+HLmuV1Ec/ie5YRq5fMO3ctgCtXarv1xhIUCUHtVtqyIgI8AP8+GB66ApudH7sBesyXpRxwxL55S0RpRE4W8uLvVPLP9/w/de9vksk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=unisoc.com; spf=pass smtp.mailfrom=unisoc.com; arc=none smtp.client-ip=222.66.158.135 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=unisoc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=unisoc.com Received: from dlp.unisoc.com ([10.29.3.86]) by SHSQR01.spreadtrum.com with ESMTP id 4492dpDj051905; Thu, 9 May 2024 10:39:51 +0800 (+08) (envelope-from zhaoyang.huang@unisoc.com) Received: from SHDLP.spreadtrum.com (bjmbx01.spreadtrum.com [10.0.64.7]) by dlp.unisoc.com (SkyGuard) with ESMTPS id 4VZbkN3NW5z2PGl6X; Thu, 9 May 2024 10:36:44 +0800 (CST) Received: from bj03382pcu01.spreadtrum.com (10.0.73.40) by BJMBX01.spreadtrum.com (10.0.64.7) with Microsoft SMTP Server (TLS) id 15.0.1497.23; Thu, 9 May 2024 10:39:48 +0800 From: "zhaoyang.huang" To: Andrew Morton , Matthew Wilcox , Jens Axboe , Tejun Heo , Josef Bacik , Baolin Wang , , , , , Zhaoyang Huang , Subject: [RFC PATCH 2/2] mm: introduce budgt control in readahead Date: Thu, 9 May 2024 10:39:37 +0800 Message-ID: <20240509023937.1090421-3-zhaoyang.huang@unisoc.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240509023937.1090421-1-zhaoyang.huang@unisoc.com> References: <20240509023937.1090421-1-zhaoyang.huang@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: quoted-printable X-ClientProxiedBy: SHCAS03.spreadtrum.com (10.0.1.207) To BJMBX01.spreadtrum.com (10.0.64.7) X-MAIL: SHSQR01.spreadtrum.com 4492dpDj051905 Content-Type: text/plain; charset="utf-8" From: Zhaoyang Huang Currently, readahead's size is decided mainly by page cache's status like hit/miss or hole size which could lead to suspension of following bio which is over the size of blk-throttle allowed size when BLK_THROTTLING is on. Introduce the budgt value here to have the bio's size be within the legal size. Signed-off-by: Zhaoyang Huang --- mm/readahead.c | 33 ++++++++++++++++++++++++--------- 1 file changed, 24 insertions(+), 9 deletions(-) diff --git a/mm/readahead.c b/mm/readahead.c index 130c0e7df99f..2b6120ced6f9 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -128,6 +128,7 @@ #include #include #include +#include =20 #include "internal.h" =20 @@ -358,16 +359,23 @@ static unsigned long get_init_ra_size(unsigned long s= ize, unsigned long max) * Get the previous window size, ramp it up, and * return it as the new window size. */ -static unsigned long get_next_ra_size(struct file_ra_state *ra, +static unsigned long get_next_ra_size(struct readahead_control *ractl, unsigned long max) { - unsigned long cur =3D ra->size; + unsigned long cur =3D ractl->ra->size; + struct inode *inode =3D ractl->mapping->host; + unsigned long budgt =3D inode->i_sb->s_bdev ? + blk_throttle_budgt(inode->i_sb->s_bdev) : 0; + unsigned long val =3D max; =20 if (cur < max / 16) - return 4 * cur; + val =3D 4 * cur; if (cur <=3D max / 2) - return 2 * cur; - return max; + val =3D 2 * cur; + + val =3D budgt ? min(budgt / PAGE_SIZE, val) : val; + + return val; } =20 /* @@ -437,6 +445,8 @@ static int try_context_readahead(struct address_space *= mapping, unsigned long max) { pgoff_t size; + unsigned long budgt =3D mapping->host->i_sb->s_bdev ? + blk_throttle_budgt(mapping->host->i_sb->s_bdev) : 0; =20 size =3D count_history_pages(mapping, index, max); =20 @@ -455,7 +465,7 @@ static int try_context_readahead(struct address_space *= mapping, size *=3D 2; =20 ra->start =3D index; - ra->size =3D min(size + req_size, max); + ra->size =3D min3(budgt / PAGE_SIZE, size + req_size, max); ra->async_size =3D 1; =20 return 1; @@ -552,6 +562,8 @@ static void ondemand_readahead(struct readahead_control= *ractl, pgoff_t index =3D readahead_index(ractl); pgoff_t expected, prev_index; unsigned int order =3D folio ? folio_order(folio) : 0; + unsigned long budgt =3D ractl->mapping->host->i_sb->s_bdev ? + blk_throttle_budgt(ractl->mapping->host->i_sb->s_bdev) : 0; =20 /* * If the request exceeds the readahead window, allow the read to @@ -574,7 +586,7 @@ static void ondemand_readahead(struct readahead_control= *ractl, 1UL << order); if (index =3D=3D expected || index =3D=3D (ra->start + ra->size)) { ra->start +=3D ra->size; - ra->size =3D get_next_ra_size(ra, max_pages); + ra->size =3D get_next_ra_size(ractl, max_pages); ra->async_size =3D ra->size; goto readit; } @@ -599,7 +611,7 @@ static void ondemand_readahead(struct readahead_control= *ractl, ra->start =3D start; ra->size =3D start - index; /* old async_size */ ra->size +=3D req_size; - ra->size =3D get_next_ra_size(ra, max_pages); + ra->size =3D get_next_ra_size(ractl, max_pages); ra->async_size =3D ra->size; goto readit; } @@ -631,6 +643,9 @@ static void ondemand_readahead(struct readahead_control= *ractl, * standalone, small random read * Read as is, and do not pollute the readahead state. */ + if (budgt) + req_size =3D min(budgt / PAGE_SIZE, req_size); + do_page_cache_ra(ractl, req_size, 0); return; =20 @@ -647,7 +662,7 @@ static void ondemand_readahead(struct readahead_control= *ractl, * Take care of maximum IO pages as above. */ if (index =3D=3D ra->start && ra->size =3D=3D ra->async_size) { - add_pages =3D get_next_ra_size(ra, max_pages); + add_pages =3D get_next_ra_size(ractl, max_pages); if (ra->size + add_pages <=3D max_pages) { ra->async_size =3D add_pages; ra->size +=3D add_pages; --=20 2.25.1