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[209.85.220.41]) by mx.google.com with SMTPS id z1sor1722224ejg.6.2019.05.06.11.18.31 for (Google Transport Security); Mon, 06 May 2019 11:18:31 -0700 (PDT) Received-SPF: pass (google.com: domain of pasha.tatashin@soleen.com designates 209.85.220.41 as permitted sender) client-ip=209.85.220.41; Authentication-Results: mx.google.com; dkim=pass header.i=@soleen.com header.s=google header.b=ZO0IGp0O; spf=pass (google.com: domain of pasha.tatashin@soleen.com designates 209.85.220.41 as permitted sender) smtp.mailfrom=pasha.tatashin@soleen.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=soleen.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=HayB7sQuY+v6EOo4zgx5AzoxFFOqeB4N5OR8XF6r5Uc=; b=ZO0IGp0OlSdXA+IWacCTnCe28YL0KDN5WLR0iOy2RQwLUXZVopK4KJfjY+7Q/z9X6s SjuXLmGb7eUbUPJHlvDgd+B3s08Ybui1oQ9ioaIhBcDsAz6stlJCXGs9JZSL5YKh43lu Nwu+fb1XhtGFgnaFbhK852KIcA+Hirr1L1Uu2CPoxojTIdKceAWJbAZ7TBO6HNLfSXLH IqZeQ9Y3ShvtCySSy+qfuIwbk91roy5qHtFp8zbKkADnaXx4F2yKU1KCdSog3LdNJZ0V /oPFwD9Z4Ilb/jEbM5g4Mp2y3Hs7tChLQ697C0ly3r+YHVZPXTFzV9DXetIRIhfLCKSy AKNA== X-Google-Smtp-Source: APXvYqwHXBTigtDuKWMtEhHCcYHo0Ym7KuPj7imSV/QN0gZyF9gZvmtmygbEq5LNv1SmyCzL2+klGlSO4LgamYmNN1E= X-Received: by 2002:a17:906:5c0f:: with SMTP id e15mr20354898ejq.151.1557166711352; Mon, 06 May 2019 11:18:31 -0700 (PDT) MIME-Version: 1.0 References: <20190502184337.20538-1-pasha.tatashin@soleen.com> <20190502184337.20538-3-pasha.tatashin@soleen.com> In-Reply-To: From: Pavel Tatashin Date: Mon, 6 May 2019 14:18:20 -0400 Message-ID: Subject: Re: [v5 2/3] mm/hotplug: make remove_memory() interface useable To: Dave Hansen Cc: Dan Williams , James Morris , Sasha Levin , Linux Kernel Mailing List , Linux MM , linux-nvdimm , Andrew Morton , Michal Hocko , Dave Hansen , Keith Busch , Vishal L Verma , Dave Jiang , Ross Zwisler , Tom Lendacky , "Huang, Ying" , Fengguang Wu , Borislav Petkov , Bjorn Helgaas , Yaowei Bai , Takashi Iwai , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , David Hildenbrand Content-Type: text/plain; charset="UTF-8" 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 Mon, May 6, 2019 at 2:04 PM Dave Hansen wrote: > > On 5/6/19 11:01 AM, Dan Williams wrote: > >>> +void __remove_memory(int nid, u64 start, u64 size) > >>> { > >>> + > >>> + /* > >>> + * trigger BUG() is some memory is not offlined prior to calling this > >>> + * function > >>> + */ > >>> + if (try_remove_memory(nid, start, size)) > >>> + BUG(); > >>> +} > >> Could we call this remove_offline_memory()? That way, it makes _some_ > >> sense why we would BUG() if the memory isn't offline. > > Please WARN() instead of BUG() because failing to remove memory should > > not be system fatal. > > That is my preference as well. But, the existing code BUG()s, so I'm > OK-ish with this staying for the moment until we have a better handle on > what all the callers do if this fails. Yes, this is the reason why I BUG() here. The current code does this, and I was not sure what would happen if we simply continue executing. Of course, I would prefer to return failure, so the callers can act appropriately, but let's make one thing at a time, this should not be part of this series. Thank you, Pasha