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 6196134FF40; Thu, 26 Mar 2026 19:25:22 +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=1774553122; cv=none; b=Bd/Sv5ym515xbZiIMF8BR2K6Q7fLP47OMDqquCAVC+RYYh4aKivv+TpodZf0wbslE2Lw5lyw7A55A0yLCgj5ACfg8OSJqu0HoLcPtZTB/w4DDW9yPskhGZ6UlT+7Vu6kIHFw/thYNhqEfEb8ItytN69R/ANY9d/KUI6+S+ViCX0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774553122; c=relaxed/simple; bh=A++szeKtnjRSEovDyZxLISgC62LFBBAIhs/d9OMRhfE=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition:In-Reply-To; b=AUPrHkOfFLbUFbqTxoCtdjkJP+GQBAgusjfSwSWFu5fpV2rIQacPopX7ps8T6PfyA2Epn+TKlMjMxD/p4e3s7/ylB87IwoTbkDDFcw0vkhZZhTfEclftPL7L3y8RG3WW/g4vHnnljqfdKf3jFiwFqPgFjak1G6H6y8yIJUNvD+0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NfJ/oEz0; 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="NfJ/oEz0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0AA1EC116C6; Thu, 26 Mar 2026 19:25:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774553122; bh=A++szeKtnjRSEovDyZxLISgC62LFBBAIhs/d9OMRhfE=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=NfJ/oEz0LRYInVcrSbNN88ZD+MdyZe+E5wpkqpNyM7Ggrd+87xrTGdb2eRZTy87DI 3AEY3FowNt2dLBx5bUv4EG4eu546MewpNXZGCLDHkBfe8g3LZwJ102n7t7khlBaszz Lx4TnfZYWvuNCDHMwl+tUFBLw2zV1Ngq0Csg3zwt51tFeRwFrtv1uYON4+pXGzeX8B iMHKIRiCjG9dp3POhWU/XzfbitypWNW1N1GDKkwoAv/NyKcEekZl9lBiRmYoXapScF rKV+yPTbfY8C2bHC3ckb0AISfTndYlJ7pwkpyfMvmqNf9+9J1OGvYPuntH/jG+z1Hp YXvuT6LOCwG0g== Date: Thu, 26 Mar 2026 14:25:20 -0500 From: Bjorn Helgaas To: Ilpo =?utf-8?B?SsOkcnZpbmVu?= Cc: linux-pci@vger.kernel.org, Bjorn Helgaas , Guenter Roeck , linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, Russell King , Geert Uytterhoeven , Thomas Bogendoerfer , "James E.J. Bottomley" , Helge Deller , Michael Ellerman , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Chris Zankel , Max Filippov , Madhavan Srinivasan , Yoshinori Sato , Rich Felker , John Paul Adrian Glaubitz , linux-kernel@vger.kernel.org, Xifer Subject: Re: [PATCH 00/10] PCI: Improve head free space usage Message-ID: <20260326192520.GA1337681@bhelgaas> Precedence: bulk X-Mailing-List: linux-alpha@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20260324165633.4583-1-ilpo.jarvinen@linux.intel.com> [+cc Xifer; thanks very much for reporting and testing!] On Tue, Mar 24, 2026 at 06:56:23PM +0200, Ilpo Järvinen wrote: > Hi all, > > This series attempts to take advantage of free head space (the free > space before the aligned start address) in order to generally produce a > tighter packing of the resources/bridge windows. > > The recent changes to the resource fitting algorithm caused resource > allocation failures in some cases where a bridge window that is sized > to be gapless could no longer be assigned. The previous algorithm left > a huge gaps which allowed it to place the remainder (non-aligning part > of the size) before the start address of used for the gapless fit, > whereas the new gapless approach always had to place the remainder > after the aligning part of the resources. There is not always space > for the remainder triggering those failures (e.g., when the aligning > part must be placed at the top of the window). > > This series attempts to allow placing the remainder once again before > the aligning part, but now without leaving huge gaps to retain the > benefits of the gapless bridge windows. The approach is somewhat hacky > but should work thanks to PCI resources fundamentally consisting only > power-of-two atoms. > > There maybe cases where architecture would not want to do such > relocation. This series adds the relocation to arch > pcibios_align_resource() functions to allow all of them taking > advantage of the better resource packing but if somebody objects doing > this relocation for a particular arch, I can remove it, please just let > me know (this relocation doesn't seem critical unless there are > regressions). > > Ilpo Järvinen (10): > resource: Add __resource_contains_unbound() for internal contains > checks > resource: Pass full extent of empty space to resource_alignf CB > resource: Rename 'tmp' variable to 'full_avail' > ARM/PCI: Remove unnecessary second application of align > am68k/PCI: Remove unnecessary second application of align > MIPS: PCI: Remove unnecessary second application of align > parisc/PCI: Cleanup align handling > PCI: Rename window_alignment() to pci_min_window_alignment() > PCI: Align head space better > PCI: Fix alignment calculation for resource size larger than align > > arch/alpha/kernel/pci.c | 1 + > arch/arm/kernel/bios32.c | 9 ++++--- > arch/m68k/kernel/pcibios.c | 8 +++++-- > arch/mips/pci/pci-generic.c | 8 ++++--- > arch/mips/pci/pci-legacy.c | 3 +++ > arch/parisc/kernel/pci.c | 17 ++++++++------ > arch/powerpc/kernel/pci-common.c | 6 ++++- > arch/s390/pci/pci.c | 1 + > arch/sh/drivers/pci/pci.c | 6 ++++- > arch/x86/pci/i386.c | 5 +++- > arch/xtensa/kernel/pci.c | 3 +++ > drivers/pci/pci.h | 3 +++ > drivers/pci/setup-bus.c | 15 ++++++++---- > drivers/pci/setup-res.c | 40 +++++++++++++++++++++++++++++++- > drivers/pcmcia/rsrc_nonstatic.c | 3 ++- > include/linux/ioport.h | 22 +++++++++++++++--- > include/linux/pci.h | 12 +++++++--- > kernel/resource.c | 33 +++++++++++++------------- > 18 files changed, 149 insertions(+), 46 deletions(-) I added Xifer's tested-by, fixed the "am68k" and missing "if" typos, and applied these to pci/resource for v7.1. Ilpo, if you post a v2 with more changes, I'll update to it. I applied the series now to get a head start on 0-day building and into next.