From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 D9B485FF13; Tue, 13 Feb 2024 16:47:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707842824; cv=none; b=fp72kPNGgQvz3Ejk6vqnssM8VMtIxFzOXke4KLQjc61DoQdBRqlfh2GY3gjaLdfalghD+S/1acYb8R5kPHIM1lx8Gy8k+inJlvosUBH7c2QsZGKj45OVO8X00LJB8Gkz9alffiWKhYM9b0zwJ5UJY7pQzS9Dp5kl2wmWfkNum7s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707842824; c=relaxed/simple; bh=fZLzxiWiWqQTQTGcyFG3odxLRJgONwBOdACD0HVg7b0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=NplBjCdAy40XW2/8K7KAMq5AqJ2l/Amnq0odKBKocnjykXFSis86bjw5QOLWeYjUzKtV4H7yadLXxIns88OxgyIzwkI9vYEZhVZD7FwFBN9ZD+afNf5I/pharTYdn5Gvd1gC3n2mXN6JSRYMWCqE0ThvZLoZ4hwVTfMIn6iTSRU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YoO0smDc; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="YoO0smDc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 55C6CC433C7; Tue, 13 Feb 2024 16:47:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1707842823; bh=fZLzxiWiWqQTQTGcyFG3odxLRJgONwBOdACD0HVg7b0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=YoO0smDcFbjVUaJydJooe2n0xA7HNBbrfT5nr/hwB/CJvoDIvNHE61hXMB+j9pp9C AKFIWh5LT4H+FMMDdkbTgyqfmnmERNCSL+SJ8bJNbbACtV9YZiIKGtBvGnmppMqRl0 0hLJDQkPLYiGU/nGrBADDZk+X0nbto40y8dplPN/7dWAiCNIcCzsTMb8acukJHx9QT IKpg1aBUkYXfOxDY7iH0Izo4xIp5JAL+PVnzRm/6dzBfGhRj86GCgyPabu4qu25ZcJ 1qZjj8wbBv/ZUbcwvd1yFwdkVWkbg0yC14O7+AmmAO4JCVwpZBWPbb6uZ4b+C2hUtA eHRaar1QTSF6g== Date: Tue, 13 Feb 2024 08:47:02 -0800 From: "Darrick J. Wong" To: "Pankaj Raghav (Samsung)" Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, mcgrof@kernel.org, gost.dev@samsung.com, akpm@linux-foundation.org, kbusch@kernel.org, chandan.babu@oracle.com, p.raghav@samsung.com, linux-kernel@vger.kernel.org, hare@suse.de, willy@infradead.org, linux-mm@kvack.org, david@fromorbit.com Subject: Re: [RFC v2 06/14] readahead: rework loop in page_cache_ra_unbounded() Message-ID: <20240213164702.GX6184@frogsfrogsfrogs> References: <20240213093713.1753368-1-kernel@pankajraghav.com> <20240213093713.1753368-7-kernel@pankajraghav.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: <20240213093713.1753368-7-kernel@pankajraghav.com> On Tue, Feb 13, 2024 at 10:37:05AM +0100, Pankaj Raghav (Samsung) wrote: > From: Hannes Reinecke > > Rework the loop in page_cache_ra_unbounded() to advance with > the number of pages in a folio instead of just one page at a time. > > Signed-off-by: Hannes Reinecke > Co-developed-by: Pankaj Raghav > Signed-off-by: Pankaj Raghav Acked-by: Darrick J. Wong --D > --- > mm/readahead.c | 13 +++++++------ > 1 file changed, 7 insertions(+), 6 deletions(-) > > diff --git a/mm/readahead.c b/mm/readahead.c > index 5e1ec7705c78..13b62cbd3b79 100644 > --- a/mm/readahead.c > +++ b/mm/readahead.c > @@ -213,7 +213,7 @@ void page_cache_ra_unbounded(struct readahead_control *ractl, > struct address_space *mapping = ractl->mapping; > unsigned long index = readahead_index(ractl); > gfp_t gfp_mask = readahead_gfp_mask(mapping); > - unsigned long i; > + unsigned long i = 0; > > /* > * Partway through the readahead operation, we will have added > @@ -231,7 +231,7 @@ void page_cache_ra_unbounded(struct readahead_control *ractl, > /* > * Preallocate as many pages as we will need. > */ > - for (i = 0; i < nr_to_read; i++) { > + while (i < nr_to_read) { > struct folio *folio = xa_load(&mapping->i_pages, index + i); > > if (folio && !xa_is_value(folio)) { > @@ -244,8 +244,8 @@ void page_cache_ra_unbounded(struct readahead_control *ractl, > * not worth getting one just for that. > */ > read_pages(ractl); > - ractl->_index++; > - i = ractl->_index + ractl->_nr_pages - index - 1; > + ractl->_index += folio_nr_pages(folio); > + i = ractl->_index + ractl->_nr_pages - index; > continue; > } > > @@ -257,13 +257,14 @@ void page_cache_ra_unbounded(struct readahead_control *ractl, > folio_put(folio); > read_pages(ractl); > ractl->_index++; > - i = ractl->_index + ractl->_nr_pages - index - 1; > + i = ractl->_index + ractl->_nr_pages - index; > continue; > } > if (i == nr_to_read - lookahead_size) > folio_set_readahead(folio); > ractl->_workingset |= folio_test_workingset(folio); > - ractl->_nr_pages++; > + ractl->_nr_pages += folio_nr_pages(folio); > + i += folio_nr_pages(folio); > } > > /* > -- > 2.43.0 > >