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Shutemov" , Michel Lespinasse , Michal =?iso-8859-1?Q?Koutn=FD?= , Song Liu , Huang Ying , Vlastimil Babka , Yang Shi , chenqiwu , Mathieu Desnoyers , John Hubbard , Thomas Hellstrom , Mike Christie , Bart Van Assche , Amit Pundir , Thomas Gleixner , Christian Brauner , Daniel Jordan , Adrian Reber , Nicolas Viennot , Al Viro , Thomas Cedeno , linux-fsdevel@vger.kernel.org, Pekka Enberg , Dave Hansen , Peter Zijlstra , Ingo Molnar , Oleg Nesterov , "Eric W. Biederman" , Jan Glauber , John Stultz , Rob Landley , Cyrill Gorcunov , "Serge E. Hallyn" , David Rientjes , Hugh Dickins , Rik van Riel , Mel Gorman , Tang Chen , Robin Holt , Shaohua Li , Sasha Levin , Johannes Weiner , Minchan Kim Subject: Re: [PATCH v5 2/2] mm: add a field to store names for private anonymous memory Message-ID: <20200819150251.GD17456@casper.infradead.org> References: <20200819141650.7462-1-sumit.semwal@linaro.org> <20200819141650.7462-3-sumit.semwal@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200819141650.7462-3-sumit.semwal@linaro.org> X-Rspamd-Queue-Id: 405BB18014AF9 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 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 Wed, Aug 19, 2020 at 07:46:50PM +0530, Sumit Semwal wrote: > +++ b/include/linux/mm_types.h > @@ -336,10 +336,18 @@ struct vm_area_struct { > /* > * For areas with an address space and backing store, > * linkage into the address_space->i_mmap interval tree. > + * > + * For private anonymous mappings, a pointer to a null terminated string > + * in the user process containing the name given to the vma, or NULL > + * if unnamed. > */ > - struct { > - struct rb_node rb; > - unsigned long rb_subtree_last; > + > + union { > + struct { > + struct rb_node rb; > + unsigned long rb_subtree_last; > + } interval; > + const char __user *anon_name; > } shared; You can significantly reduce the size of this patch by doing this instead: union { struct { struct rb_node rb; unsigned long rb_subtree_last; } shared; const char __user *anon_name; };