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 2EA44C4345F for ; Sun, 28 Apr 2024 20:59:29 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 51C9A6B007B; Sun, 28 Apr 2024 16:59:28 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4CCCC6B0083; Sun, 28 Apr 2024 16:59:28 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3BCA06B0085; Sun, 28 Apr 2024 16:59:28 -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 1EEEF6B007B for ; Sun, 28 Apr 2024 16:59:28 -0400 (EDT) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 9D60D80378 for ; Sun, 28 Apr 2024 20:59:27 +0000 (UTC) X-FDA: 82060156374.01.E1FF51F Received: from mout-p-201.mailbox.org (mout-p-201.mailbox.org [80.241.56.171]) by imf17.hostedemail.com (Postfix) with ESMTP id A69A740003 for ; Sun, 28 Apr 2024 20:59:25 +0000 (UTC) Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=pankajraghav.com header.s=MBO0001 header.b=OwNofpHv; spf=pass (imf17.hostedemail.com: domain of kernel@pankajraghav.com designates 80.241.56.171 as permitted sender) smtp.mailfrom=kernel@pankajraghav.com; dmarc=pass (policy=quarantine) header.from=pankajraghav.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1714337966; 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=oVuobLMQ/P3jplHXQkykRM7/2IOlzm4DqmyFCcCzMHA=; b=7Dp6113WGiqOr0sfywvHvwiY8eJO/37hCEfizrhxeSSLNgQIPhUhFXzCHhvind1fLGrJfp CbkCXvdwk+VvqPGApwHFxf7iNvDrEPNvoqXeezInqQFyBF/MK1C6Ag95ak+nJnTagCfKPh SFI7kF4vk00txrSB6ItIzY7v/7MPnPA= ARC-Authentication-Results: i=1; imf17.hostedemail.com; dkim=pass header.d=pankajraghav.com header.s=MBO0001 header.b=OwNofpHv; spf=pass (imf17.hostedemail.com: domain of kernel@pankajraghav.com designates 80.241.56.171 as permitted sender) smtp.mailfrom=kernel@pankajraghav.com; dmarc=pass (policy=quarantine) header.from=pankajraghav.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1714337966; a=rsa-sha256; cv=none; b=gDeZ5CeCsmCjzXR2VB7Ov2Nbxfabo7iVaa5Z6amJNrYeZbFbP9bH8je9NC7NonO3bSOYFZ VRNs0Iqr6LiL91g4oMdRGok9fQAPA0+9hXV5yZfdNLnrkyG2UmlHXl+ZM7eyGtAPKD+gKx JrhchcRW8wOCRS7Q3izKBfruwBGhk7Y= Received: from smtp202.mailbox.org (smtp202.mailbox.org [IPv6:2001:67c:2050:b231:465::202]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-201.mailbox.org (Postfix) with ESMTPS id 4VSJjh61y0z9sf0; Sun, 28 Apr 2024 22:59:20 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pankajraghav.com; s=MBO0001; t=1714337960; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=oVuobLMQ/P3jplHXQkykRM7/2IOlzm4DqmyFCcCzMHA=; b=OwNofpHvCUzTevzwB69MRfcQ4Fbi9zpzM6X5SMfGDBgzn3gynhVV3LCVn3LOwQ2HO96cvw DVDgfgtvtk05RPjYW9QK0rOq4ILVukQC028R4OuVS+CdvMa02NGQC3PLcJHXzg2GDF+fLL Gonw0LlGjlTVqv5AAt8Wb0azbPYvxm5hLx9HUkms218f08GeKdoMw34qjq3VxP+t+VqIeI kMlA1FGAp2VKojjNTlYn//rLUvKx0HZF+G89IMQH8zJ0TShQ1Uptu/KpRlupH+VJSAoZOq 0sMQlXX7XK9JWk+7JKJ+B9turL0HbIhJocLidmpM5TRDcazcHFFa1FM+fPB5Xg== Date: Sun, 28 Apr 2024 20:59:15 +0000 From: "Pankaj Raghav (Samsung)" To: "Darrick J. Wong" 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: <20240428205915.2iocwkcf3edc5y2k@quentin> References: <20240425113746.335530-1-kernel@pankajraghav.com> <20240425113746.335530-4-kernel@pankajraghav.com> <20240426151243.GD360919@frogsfrogsfrogs> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240426151243.GD360919@frogsfrogsfrogs> X-Rspam-User: X-Rspamd-Queue-Id: A69A740003 X-Rspamd-Server: rspam06 X-Stat-Signature: kgdkxn553oete8jbjixn6naacrutysuh X-HE-Tag: 1714337965-113465 X-HE-Meta: U2FsdGVkX1/Zd/pe+mnSw7FvdwUFb0/g0o+FTgcBw8j7qRR8BjtjXZAN2O6AyOoRR7zdc8uRKaOSXJpLW/lqJEPB8emAGSwWdNRBoWj+hCLrlVeSqlu39XxNED7eIO3B+tLsyT0dIi0yOC8q3PB8ZUIg7CrWWXagZe2Q1nuFHjsNqTYSS07XlY5ohX0a32rUfImyg9VZt2OhChxES+z8jF0L+vfnSnyJQf+bF7M+8XFCrcAxmaou6h4P+ss4v6YNWfpJXNQMEamIxNPxKG3Cm7bUl2itaJv41uC8cUGBvadG5gkPrLtihLhRzS3Dkc5Ah6T0IpIm3MG3/g41VYnbz8L2OzU38T88N8MtwbAJ3VhXg32aLsrmhZtE1dzggNuNy95riEJqVS6+KvrFd+ncL5SCg1gHO9NB1OFcDVJPlAi3d9OLVCV4kU2xYRWsnVBDiiVVAZiNMEJS3YzW7HeZepeTKzN8yM1SsROo/yjcFcGXA2E4z4Tyhwn7rKGWPqPqc9rDRorTnJGWbBvIus7icQxCn3lWl3DPcdku70Ll757RVG22SxoWrq5LQzkeP6CQMU9uu2vpvoTXeGYR/hVKF2hIIiXmMlP4shS+y/KedJLTZL2FyuaUBeBwJIWA44PoqpIqMLxFoNq02ND/hDQ6ATG/JfaNW0fL+QPs8cQeOkQmVBeL1cEfEb4Z+FOV5G/xYO4/ixBYFPZQk08m4wGXaW2MfxGfYLB/H0YS5Y8wd6ErTXCH/qFjbJx/wGd4nMGE+XUizTz6lb1S+qMUGhicJz3z9YUi9sXps5luJF9mgSnON4sXGTH1GVTxmvsZi4qVGWt6N/etXDUEqjt4egeVCd3jBpk+QfXoYQF8on0x/lQ1xQMN6Jt12nLAsNztmjYpJJczWSwCsXS+rSHzUaB6idvaJNBMaDfUNUm4uQK3nWQJ39R7L1OI5SbLCU0V/FagpspMZ1Orludy5z+ZTYN rot9T7aC 3X6ZVVqA8e+26o/w4GqD1zIfDBkgIxnQc4bOv8A/LeoWZakOQAbU/twnAXc3wH4Ud8CFtvExjqPolW5v0z9OL0WKHTLbvHktTKky/14nqx+3KtqNeWySlOggIQlye35LLCH+OCaEgEdJaE1S5ntefNNYkW/pnD5VvE7L0ILLzud4S0TnVBuGav7OfaJgby/W4z1rk+kR4/ZKns/TglUtQyJ2MXzV1H6DL1xu1MZbLyS0CuyB/uXz55N5wd5tnRq4/aQfXFeN3OOI6Rvnk1pmiAWG28IAnWBwd723sVCXxfMQxggKyDnSJ9/ywsioDJyogkvgv3PthIGP0dX1FaEgPXDOzQ69X6VqMKKeL 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 Fri, Apr 26, 2024 at 08:12:43AM -0700, Darrick J. Wong wrote: > 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 Yes. We will get a ENOMEM if we cannot allocate min_order size folio. :) Thanks! > > --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 > > > >