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Date: Thu, 20 Jul 2023 08:47:44 +0200
From: Christoph Hellwig <hch@lst.de>
To: Petr Tesarik <petrtesarik@huaweicloud.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>,
	Russell King <linux@armlinux.org.uk>,
	Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	"maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" <x86@kernel.org>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	Juergen Gross <jgross@suse.com>,
	Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>,
	Christoph Hellwig <hch@lst.de>,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	Robin Murphy <robin.murphy@arm.com>,
	Petr Tesarik <petr.tesarik.ext@huawei.com>,
	Jonathan Corbet <corbet@lwn.net>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Hans de Goede <hdegoede@redhat.com>, James Seo <james@equiv.tech>,
	James Clark <james.clark@arm.com>,
	Kees Cook <keescook@chromium.org>,
	"moderated list:XEN HYPERVISOR ARM" <xen-devel@lists.xenproject.org>,
	"moderated list:ARM PORT" <linux-arm-kernel@lists.infradead.org>,
	open list <linux-kernel@vger.kernel.org>,
	"open list:MIPS" <linux-mips@vger.kernel.org>,
	"open list:XEN SWIOTLB SUBSYSTEM" <iommu@lists.linux.dev>,
	Roberto Sassu <roberto.sassu@huaweicloud.com>,
	Kefeng Wang <wangkefeng.wang@huawei.com>, petr@tesarici.cz
Subject: Re: [PATCH v4 8/8] swiotlb: search the software IO TLB only if a
 device makes use of it
Message-ID: <20230720064744.GA4395@lst.de>
References: <cover.1689261692.git.petr.tesarik.ext@huawei.com> <a8d31d3fffa0867dce2b44b98dc2714289edfdc9.1689261692.git.petr.tesarik.ext@huawei.com>
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User-Agent: Mutt/1.5.17 (2007-11-01)

Any reason this can't just do a list_empty_careful on the list
instead of adding yet another field that grows struct device?