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[221.241.217.81]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-7205794f996sm1023825b3a.93.2024.10.25.05.55.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 25 Oct 2024 05:55:10 -0700 (PDT) Date: Fri, 25 Oct 2024 21:55:06 +0900 Message-ID: From: Hajime Tazaki To: johannes@sipsolutions.net Cc: linux-um@lists.infradead.org, jdike@addtoit.com, richard@nod.at, anton.ivanov@cambridgegreys.com, ricarkol@google.com Subject: Re: [RFC PATCH 03/13] um: nommu: memory handling In-Reply-To: References: <304383e5c9b2bba18678598bbdacadc9126d8f74.1729770373.git.thehajime@gmail.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) Emacs/26.3 Mule/6.0 MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241025_135515_041937_6AA1FBED X-CRM114-Status: GOOD ( 17.73 ) X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" Errors-To: linux-um-bounces+linux-um=archiver.kernel.org@lists.infradead.org On Fri, 25 Oct 2024 18:11:01 +0900, Johannes Berg wrote: > > (I should say, I'm still reading through this, and haven't formed an > overall opinion. Just nitpicking on the details as I see them for now) thanks anyway. looking forward to any opinions. > > +#endif > > + > > > > #include > > extra newline will fix it. > > /* tlb.c */ > > +#ifdef CONFIG_MMU > > extern void report_enomem(void); > > +#else > > +static inline void report_enomem(void) > > +{ > > +} > > +#endif > > Should that really do _nothing_? Perhaps it's not called at all in no- > MMU, but then you don't need it, but otherwise it seems it should do > something even if it's just panic()? it is called also in !MMU. I'll think to figure out how the function is shared. > > > brk_end = (unsigned long) UML_ROUND_UP(sbrk(0)); > > +#ifdef CONFIG_MMU > > map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0); > > +#else > > + map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 1); > > +#endif > > That seems much simpler as > > map_memory(....., > !IS_ENABLED(CONFIG_MMU)); looks nice, will fix it. > > +#ifdef UML_CONFIG_MMU > > loc = mmap64((void *) virt, len, prot, MAP_SHARED | MAP_FIXED, > > fd, off); > > +#else > > + loc = mmap64((void *) virt, len, prot, MAP_SHARED | MAP_FIXED | MAP_ANONYMOUS, > > + fd, off); > > +#endif > > Same here, > > mmap64(.... > MAP_SHARED | MAP_FIXED | > IS_ENABLED(CONFIG_MMU) ? MAP_ANONYMOUS : 0, > ...); since this is part under os-Linux and we cannot use kconfig.h (IIUC) feature (e.g., IS_ENABLED). but I'll reformat it to simplify instead of duplicating same lines. -- Hajime