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[109.81.94.157]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-368786944c8sm1637719f8f.54.2024.07.19.06.30.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 19 Jul 2024 06:30:55 -0700 (PDT) Date: Fri, 19 Jul 2024 15:30:54 +0200 From: Michal Hocko To: Barry Song <21cnbao@gmail.com> Cc: Vlastimil Babka , akpm@linux-foundation.org, linux-mm@kvack.org, Barry Song , Uladzislau Rezki , Christoph Hellwig , Lorenzo Stoakes , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , 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: <031ff35b-65f0-4ead-a08f-21711bad5e29@suse.cz> <4a1bd482-bfff-4843-a60f-004b3a8a99e4@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Stat-Signature: t34u9q4igprho673sdqwjxaxh491jb7c X-Rspam-User: X-Rspamd-Queue-Id: 3EA0020021 X-Rspamd-Server: rspam02 X-HE-Tag: 1721395857-195748 X-HE-Meta: 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 2+NZPO6h wvpanr5kakfF5vMKtjXKjB4vSFaRy3waNNDurQZnbnZhwQoL0SUvNF5vHzqA9MYjFD1CpkUEGd9AQlraj2d6oK+ccu7RRPDqjSTcW8z2++Luc/v7a6ePdJN1lj/n7APe4v6G2E5mwIaO3kr7lRsFn5F+Z/LtWCcybJKv8KXaxtPJIByDdDUBPQPDPSWBxOT1g+AZul3hAzs+EDxX6QUoTFZNznUXBQZsuy8SB+445KLpIFTU1pIUZDDZHC49Ok9rQNZcELTH7EoqeWPCVk2FncChpSRJvghf5asiwpb6RUjQt8LwfMRY7mou1U43qr4uZm6jnIQJ10p3HD4JNABpKrBGe+z9/Ly/3NZ1teGdFdJtJkqgZir+IS6Xlvh/jo5CV5d0S9soNDsTiZLExRX7hXGH0MA== 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 21:02:10, Barry Song wrote: > what about an earlier WARN_ON, for example, even before we begin to > try the allocation? Page allocator is a hot path and adding checks for something that shouldn't really even exist is not a great addition there IMHO. -- Michal Hocko SUSE Labs