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[31.46.241.165]) by smtp.gmail.com with ESMTPSA id ku21-20020a170907789500b00a517e505e3bsm527610ejc.204.2024.04.11.01.43.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 11 Apr 2024 01:43:14 -0700 (PDT) Sender: Ingo Molnar Date: Thu, 11 Apr 2024 10:43:12 +0200 From: Ingo Molnar To: Nikita Kiryushin Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Peter Zijlstra , Ashok Raj , David Woodhouse , linux-kernel@vger.kernel.org, lvc-project@linuxtesting.org Subject: Re: [PATCH] x86/smpboot: Add map vars allocation check in smp_prepare_cpus_common Message-ID: References: <20240409182940.664482-1-kiryushin@ancud.ru> <75c2b85a-da67-4037-b2b5-6a1dec838fa9@ancud.ru> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <75c2b85a-da67-4037-b2b5-6a1dec838fa9@ancud.ru> * Nikita Kiryushin wrote: > But I have some questions considering __GFP_NOFAIL. It clearly shows, > that allocation will not fail/is not expected to fail, does it not try > making allocation until it succeeds? Would not it make the system hang in > a problematic case? Yes, which is better than undefined behavior. This case should only happen on hopelessly buggy kernels or hopelessly buggy hardware - which will very likely crash way sooner before they get into this part of the init sequence. This whole problem is a non-issue. Thanks, Ingo