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[2607:7c80:54:e::133]) by mx.google.com with ESMTPS id y70si15342157pgd.359.2019.04.04.12.32.14 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 04 Apr 2019 12:32:14 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of willy@infradead.org designates 2607:7c80:54:e::133 as permitted sender) client-ip=2607:7c80:54:e::133; Authentication-Results: mx.google.com; dkim=pass header.i=@infradead.org header.s=bombadil.20170209 header.b="I/nIbvmP"; spf=pass (google.com: best guess record for domain of willy@infradead.org designates 2607:7c80:54:e::133 as permitted sender) smtp.mailfrom=willy@infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=dRdt+9F2fFh2MhgOyplKH+n+b53N1s6QD7kx64loto4=; b=I/nIbvmPJtHr+wQsd1QkHPBpB kc5Bg4JxKe9J5KCjzwH6yibPkA+4RP1ZcrR6AZWCTeoRV+JKP2NYqDafAUH5LfxmvzdrENJfWyOO5 yw3VI7GcU4EpCZdLevkjX8+hUJFACFBL1omI+JouUs+Fc1aB9KbgpAdH5xWgwfCnwodyMeHVHYROd W5xUwV/lT4o2io08HRRJBBZGUvqZ73KtTXlr2qFV6nksBg1+vn4+TAkyIrzaS/Xvajc1gJPhQkETn 89zgzkbaImuJWeuwJMqPHg9EYkFEGbCLjdBJmULGoCfynL1q4E+4D/QYsMc1am9xmcLRf5OVTZIQv 9XLbRQo8w==; Received: from willy by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1hC85s-0006uZ-1H; Thu, 04 Apr 2019 19:32:12 +0000 Date: Thu, 4 Apr 2019 12:32:11 -0700 From: Matthew Wilcox To: Dan Williams Cc: linux-kernel@vger.kernel.org, Keith Busch , vishal.l.verma@intel.com, x86@kernel.org, linux-mm@kvack.org, linux-nvdimm@lists.01.org Subject: Re: [RFC PATCH 2/5] lib/memregion: Uplevel the pmem "region" ida to a global allocator Message-ID: <20190404193211.GK22763@bombadil.infradead.org> References: <155440490809.3190322.15060922240602775809.stgit@dwillia2-desk3.amr.corp.intel.com> <155440491849.3190322.17551464505265122881.stgit@dwillia2-desk3.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <155440491849.3190322.17551464505265122881.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: Mutt/1.9.2 (2017-12-15) 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: On Thu, Apr 04, 2019 at 12:08:38PM -0700, Dan Williams wrote: > +++ b/lib/Kconfig > @@ -318,6 +318,12 @@ config DECOMPRESS_LZ4 > config GENERIC_ALLOCATOR > bool > > +# > +# Generic IDA for memory regions > +# Leaky abstraction -- nobody needs know that it's implemented as an IDA. Suggest: # Memory region ID allocation ... > +++ b/lib/memregion.c > @@ -0,0 +1,22 @@ > +#include > +#include > + > +static DEFINE_IDA(region_ida); > + > +int memregion_alloc(void) > +{ > + return ida_simple_get(®ion_ida, 0, 0, GFP_KERNEL); > +} > +EXPORT_SYMBOL(memregion_alloc); > + > +void memregion_free(int id) > +{ > + ida_simple_remove(®ion_ida, id); > +} > +EXPORT_SYMBOL(memregion_free); > + > +static void __exit memregion_exit(void) > +{ > + ida_destroy(®ion_ida); > +} > +module_exit(memregion_exit); - Should these be EXPORT_SYMBOL_GPL? - Can we use the new interface, ida_alloc() and ida_free()? - Do we really want memregion_exit() to happen while there are still IDs allocated in the IDA? I think this might well be better as: BUG_ON(!ida_empty(®ion_ida)); Also, do we really want to call the structure the region_ida? Why not region_ids?