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[109.81.94.157]) by smtp.gmail.com with ESMTPSA id 4fb4d7f45d1cf-5a30a4d6e67sm7895632a12.17.2024.07.23.11.53.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Jul 2024 11:53:07 -0700 (PDT) Date: Tue, 23 Jul 2024 20:53:06 +0200 From: Michal Hocko To: Danilo Krummrich Cc: cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, vbabka@suse.cz, roman.gushchin@linux.dev, 42.hyeyoo@gmail.com, urezki@gmail.com, hch@infradead.org, kees@kernel.org, ojeda@kernel.org, wedsonaf@gmail.com, mpe@ellerman.id.au, chandan.babu@oracle.com, christian.koenig@amd.com, maz@kernel.org, oliver.upton@linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org, rust-for-linux@vger.kernel.org Subject: Re: [PATCH v2 2/2] mm: kvmalloc: align kvrealloc() with krealloc() Message-ID: References: <20240722163111.4766-1-dakr@kernel.org> <20240722163111.4766-3-dakr@kernel.org> Precedence: bulk X-Mailing-List: rust-for-linux@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: On Tue 23-07-24 15:33:32, Danilo Krummrich wrote: > On Tue, Jul 23, 2024 at 02:12:23PM +0200, Michal Hocko wrote: > > On Tue 23-07-24 13:55:48, Danilo Krummrich wrote: [...] > > void *kvrealloc_noprof(const void *p, size_t size, gfp_t flags) > > { > > void *newp; > > > > if (!size && p) { > > kvfree(p); > > return NULL; > > } > > > > if (!is_vmalloc_addr(p)) > > newp = krealloc_noprof(p, size, kmalloc_gfp_adjust(flags, size)); > > > > if (newp) > > return newp; > > > > return vrealloc_noprof(p, size, flags); > > } > > EXPORT_SYMBOL(kvrealloc_noprof); > > This looks weird. The fact that you're passing p to vrealloc_noprof() if > krealloc_noprof() fails, implies that vrealloc_noprof() must be able to deal > with pointers to kmalloc'd memory. You are right I have oversimplified this. I was hoping to follow kvmalloc model with a clear fallback and that should be possible but it would require more changes. Scratch that. -- Michal Hocko SUSE Labs