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[109.81.94.157]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-368786944c8sm1115215f8f.54.2024.07.19.02.45.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 19 Jul 2024 02:45:27 -0700 (PDT) Date: Fri, 19 Jul 2024 11:45:26 +0200 From: Michal Hocko To: Barry Song <21cnbao@gmail.com> Cc: akpm@linux-foundation.org, linux-mm@kvack.org, Barry Song , Uladzislau Rezki , Christoph Hellwig , Lorenzo Stoakes , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Vlastimil Babka , Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com> Subject: Re: [PATCH RFC] mm: warn potential return NULL for kmalloc_array and kvmalloc_array with __GFP_NOFAIL Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 0C9A11C0023 X-Stat-Signature: pj4sxzgoappps5qhomizr8twh343heok X-Rspam-User: X-HE-Tag: 1721382329-774789 X-HE-Meta: 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 P+W3kGJq bXy4LlQB09wdsUFLDXZx6mC/oCY9/5zJyCr2MOA2kzCGmeUROZiKwpaf93Uq/Y+XvOgSKGWP3vVPL4CcpKs30MxPiMZapxTr38U90Kt0iAGnOc4vGBMxZwaNf3aW5GSqSxrVabAHlaa377JntyRdArCprU+XVraz5M2I1lkK4HNp2Av0eJN3koDrccnWTry1Ri6TLV6f4nbhe17ENkO7P0uh36//jW+mXCKR8vsOISq62/iAFit9A+3JhSf1CRUjwwoa4a/+VFV/W+pC+K7rF1dhwDHVknuYgwE6yqivclPSQCCrFTV+WJBvh+I+NjGkrZCV5Otx+y2hEBHsbLgiFw2UivVaMQJMYa9DToLGtAbgUmWmnZEXoKKlzsvHF0CRc1wZYvd/oyhQaEAtKPTMTnT8RBA== 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: List-Subscribe: List-Unsubscribe: On Fri 19-07-24 21:36:38, Barry Song wrote: > And I believe that even most MM experts have no idea when GFP_NOFAIL > will fail. This is so bad to keep it as is. GFP_NOFAIL doesn't fail in any supported scenarios. We are talking how to deal with those that are unsupported. I am not sure how much helpful it is to document all potential gfp combinations that make no-sense. -- Michal Hocko SUSE Labs