From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9D737C4345F for ; Fri, 26 Apr 2024 15:12:50 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 366C66B009A; Fri, 26 Apr 2024 11:12:50 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 317876B009B; Fri, 26 Apr 2024 11:12:50 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1DF716B009C; Fri, 26 Apr 2024 11:12:50 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id F32496B009A for ; Fri, 26 Apr 2024 11:12:49 -0400 (EDT) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id B978B1409CC for ; Fri, 26 Apr 2024 15:12:49 +0000 (UTC) X-FDA: 82052025258.19.482B0C4 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by imf21.hostedemail.com (Postfix) with ESMTP id 77AEF1C0010 for ; Fri, 26 Apr 2024 15:12:47 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=UW5Mm8BC; spf=pass (imf21.hostedemail.com: domain of djwong@kernel.org designates 145.40.73.55 as permitted sender) smtp.mailfrom=djwong@kernel.org; dmarc=pass (policy=none) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1714144368; a=rsa-sha256; cv=none; b=O0Ws8J4XL98UVrxKJfj9AzVqr8rq1zRXfNTluPeChL/A77UZi2OhqgRq87Opr+XJBr71Ed v85cKbZRJmMe0ZF4ZknVLlIn9k4YPklraNxMbLTLnT7liXUYjAwL4LH5bhTyJvxkzDlnNI WuFkcU5qcLJfld11aQgvL6zOPgp7vYk= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=UW5Mm8BC; spf=pass (imf21.hostedemail.com: domain of djwong@kernel.org designates 145.40.73.55 as permitted sender) smtp.mailfrom=djwong@kernel.org; dmarc=pass (policy=none) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1714144368; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=IddlXkr1+T726xExwi34qtwH4Jtu3JiJ70Mypy2hT9g=; b=6Y0dwAwJ189F58ROnuZM6QcwD3Y9GuhyLADwHGE6rmbO/9+rb3LuamRANX4M5gMospKBVd iGDXUr4/Zbwgi4i0wxVaoakri4YasQUfogw6TIOTGFuWiqCYJ0wO/hkBhZ7uQcjQSE1nPT sbRemiFR8GWFlMYHLww1N3KO8RC6F0g= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sin.source.kernel.org (Postfix) with ESMTP id 80B81CE1B1E; Fri, 26 Apr 2024 15:12:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9E65AC113CD; Fri, 26 Apr 2024 15:12:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1714144363; bh=quc7LSiSVw2TT07uTSXycfAYUCFeYT8rW3NArklrOJQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=UW5Mm8BCg0Roek5VE0mS5z+hU4Rliru5i4lxsEb6rJbZNPG0GNrdQRtkDQxnb70A2 wmpqBhMuWvX5vGpb/2QoMAZMZy21JdccdODDRNV9qwEWubFJPpfan9sSS4Qyj24qlH 88zpKEYRbBIkLYo1GadptPit6L8NfZzsA4kDQ+N6O5EJtsfweFTlyvwJZvMmuQSMEV pmwDFrf+V1zCLYFN6Mhifq6VU5a6avVs1dtBi5wwRIRZ7u3u0EAMkIeB+2j4h9DIvw sgRikwxLLz/3cs9yEEkwnKP6YLlXjH1MHlncJkACn31uQsj5kLJVkBkjUJ2b44RNEi xdA+KkNkUUcYw== Date: Fri, 26 Apr 2024 08:12:43 -0700 From: "Darrick J. Wong" To: "Pankaj Raghav (Samsung)" Cc: willy@infradead.org, brauner@kernel.org, david@fromorbit.com, chandan.babu@oracle.com, akpm@linux-foundation.org, linux-fsdevel@vger.kernel.org, hare@suse.de, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-xfs@vger.kernel.org, mcgrof@kernel.org, gost.dev@samsung.com, p.raghav@samsung.com Subject: Re: [PATCH v4 03/11] filemap: allocate mapping_min_order folios in the page cache Message-ID: <20240426151243.GD360919@frogsfrogsfrogs> References: <20240425113746.335530-1-kernel@pankajraghav.com> <20240425113746.335530-4-kernel@pankajraghav.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240425113746.335530-4-kernel@pankajraghav.com> X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 77AEF1C0010 X-Stat-Signature: 6uts8ne9chg91ro3s3ahfm1qpy7rboi7 X-Rspam-User: X-HE-Tag: 1714144367-887832 X-HE-Meta: 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 OBF+s3Da d69UkNIF7k+0kOIDsLiUHmENiajLWlexgpmKLi9WXLCIpv26sx5KKfLUGSGTVE86JIDF31HNZ/Dt3q2PF39/PuN5SUt7csMOhpGV2nc733NEqUR6Qn75ugxS0vHBDNSpYWByOwkjH0l5f1k4LqDbD7pLLPmJ5MjuieZMT3YFvpcLDuoOm9PKCU1oMp6Z5haARxXSZLXKzhQrzZZrRdKoBtye3HsKc+/PxIoufvPGMDiv1MiSnRwD7mkCg+tKA/2Ey6v2DCtVU6TvbxDaQqQi1SClMOttLfp0SyynshGWk1Z1TaeR+YKNpcF6mkAvnuZWeSBY3 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, Apr 25, 2024 at 01:37:38PM +0200, Pankaj Raghav (Samsung) wrote: > From: Luis Chamberlain > > filemap_create_folio() and do_read_cache_folio() were always allocating > folio of order 0. __filemap_get_folio was trying to allocate higher > order folios when fgp_flags had higher order hint set but it will default > to order 0 folio if higher order memory allocation fails. > > Supporting mapping_min_order implies that we guarantee each folio in the > page cache has at least an order of mapping_min_order. When adding new > folios to the page cache we must also ensure the index used is aligned to > the mapping_min_order as the page cache requires the index to be aligned > to the order of the folio. If we cannot find a folio of at least min_order size, what error is sent back? If the answer is "the same error that you get if we cannot allocate a base page today (aka ENOMEM)", then I think I understand this enough to say Reviewed-by: Darrick J. Wong --D > Signed-off-by: Luis Chamberlain > Co-developed-by: Pankaj Raghav > Signed-off-by: Pankaj Raghav > --- > mm/filemap.c | 24 +++++++++++++++++------- > 1 file changed, 17 insertions(+), 7 deletions(-) > > diff --git a/mm/filemap.c b/mm/filemap.c > index 30de18c4fd28..f0c0cfbbd134 100644 > --- a/mm/filemap.c > +++ b/mm/filemap.c > @@ -858,6 +858,8 @@ noinline int __filemap_add_folio(struct address_space *mapping, > > VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio); > VM_BUG_ON_FOLIO(folio_test_swapbacked(folio), folio); > + VM_BUG_ON_FOLIO(folio_order(folio) < mapping_min_folio_order(mapping), > + folio); > mapping_set_update(&xas, mapping); > > if (!huge) { > @@ -1895,8 +1897,10 @@ struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index, > folio_wait_stable(folio); > no_page: > if (!folio && (fgp_flags & FGP_CREAT)) { > - unsigned order = FGF_GET_ORDER(fgp_flags); > + unsigned int min_order = mapping_min_folio_order(mapping); > + unsigned int order = max(min_order, FGF_GET_ORDER(fgp_flags)); > int err; > + index = mapping_align_start_index(mapping, index); > > if ((fgp_flags & FGP_WRITE) && mapping_can_writeback(mapping)) > gfp |= __GFP_WRITE; > @@ -1936,7 +1940,7 @@ struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index, > break; > folio_put(folio); > folio = NULL; > - } while (order-- > 0); > + } while (order-- > min_order); > > if (err == -EEXIST) > goto repeat; > @@ -2425,13 +2429,16 @@ static int filemap_update_page(struct kiocb *iocb, > } > > static int filemap_create_folio(struct file *file, > - struct address_space *mapping, pgoff_t index, > + struct address_space *mapping, loff_t pos, > struct folio_batch *fbatch) > { > struct folio *folio; > int error; > + unsigned int min_order = mapping_min_folio_order(mapping); > + pgoff_t index; > > - folio = filemap_alloc_folio(mapping_gfp_mask(mapping), 0); > + folio = filemap_alloc_folio(mapping_gfp_mask(mapping), > + min_order); > if (!folio) > return -ENOMEM; > > @@ -2449,6 +2456,8 @@ static int filemap_create_folio(struct file *file, > * well to keep locking rules simple. > */ > filemap_invalidate_lock_shared(mapping); > + /* index in PAGE units but aligned to min_order number of pages. */ > + index = (pos >> (PAGE_SHIFT + min_order)) << min_order; > error = filemap_add_folio(mapping, folio, index, > mapping_gfp_constraint(mapping, GFP_KERNEL)); > if (error == -EEXIST) > @@ -2509,8 +2518,7 @@ static int filemap_get_pages(struct kiocb *iocb, size_t count, > if (!folio_batch_count(fbatch)) { > if (iocb->ki_flags & (IOCB_NOWAIT | IOCB_WAITQ)) > return -EAGAIN; > - err = filemap_create_folio(filp, mapping, > - iocb->ki_pos >> PAGE_SHIFT, fbatch); > + err = filemap_create_folio(filp, mapping, iocb->ki_pos, fbatch); > if (err == AOP_TRUNCATED_PAGE) > goto retry; > return err; > @@ -3708,9 +3716,11 @@ static struct folio *do_read_cache_folio(struct address_space *mapping, > repeat: > folio = filemap_get_folio(mapping, index); > if (IS_ERR(folio)) { > - folio = filemap_alloc_folio(gfp, 0); > + folio = filemap_alloc_folio(gfp, > + mapping_min_folio_order(mapping)); > if (!folio) > return ERR_PTR(-ENOMEM); > + index = mapping_align_start_index(mapping, index); > err = filemap_add_folio(mapping, folio, index, gfp); > if (unlikely(err)) { > folio_put(folio); > -- > 2.34.1 > >