Sender: Guenter Roeck <groeck7@gmail.com>
Date:   Mon, 27 Feb 2023 18:18:08 -0800
From:   Guenter Roeck <linux@roeck-us.net>
To:     Keith Busch <kbusch@kernel.org>
Cc:     Keith Busch <kbusch@meta.com>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, willy@infradead.org, hch@lst.de,
        tonyb@cybernetics.com, akpm@linux-foundation.org,
        kernel-team@meta.com
Subject: Re: [PATCHv4 11/12] dmapool: link blocks across pages
Message-ID: <20230228021808.GB3955901@roeck-us.net>
References: <20230126215125.4069751-1-kbusch@meta.com>
 <20230126215125.4069751-12-kbusch@meta.com>
 <20230227005445.GA3425881@roeck-us.net>
 <Y/1SfK4//04Tznvy@kbusch-mbp.dhcp.thefacebook.com>
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In-Reply-To: <Y/1SfK4//04Tznvy@kbusch-mbp.dhcp.thefacebook.com>
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On Mon, Feb 27, 2023 at 06:01:48PM -0700, Keith Busch wrote:
> On Sun, Feb 26, 2023 at 04:54:45PM -0800, Guenter Roeck wrote:
> > With this patch in linux-next, I see a boot failure when trying to boot
> > a powernv qemu emulation from the SCSI MEGASAS controller.
> > 
> > Qemu command line is
> > 
> > qemu-system-ppc64 -M powernv -cpu POWER9 -m 2G \
> > 	-kernel arch/powerpc/boot/zImage.epapr \
> > 	-snapshot \
> > 	-device megasas,id=scsi,bus=pcie.0 -device scsi-hd,bus=scsi.0,drive=d0 \
> > 	-drive file=rootfs-el.ext2,format=raw,if=none,id=d0 \
> > 	-device i82557a,netdev=net0,bus=pcie.1 -netdev user,id=net0 \
> > 	-nographic -vga none -monitor null -no-reboot \
> > 	--append "root=/dev/sda console=tty console=hvc0"
> > 
> > Reverting this patch together with "dmapool: create/destroy cleanup"
> > fixes the problem.
> 
> Thanks for the notice. I was able to recreate, and it does look like this is
> fixed with my more recent update changing the dma pool block order, and that is
> still pending out of tree. Would you also be able to verify? The patch is
> available here:
> 
>   https://lore.kernel.org/linux-mm/Y%2FzmUXrAiNujjoib@kbusch-mbp.dhcp.thefacebook.com/T/#t

Yes, that fixes the problem I have observed. I sent a Tested-by:
a minute ago.

Guenter