2011/4/12 Greg KH <greg@xxxxxxxxx>: > On Tue, Apr 12, 2011 at 12:12:47AM +0200, RafaÅ MiÅecki wrote: >> 2011/4/11 Greg KH <greg@xxxxxxxxx>: >> > On Mon, Apr 11, 2011 at 11:36:39PM +0200, RafaÅ MiÅecki wrote: >> >> 2011/4/11 Greg KH <greg@xxxxxxxxx>: >> >> > Please read the documentation for how to do this properly. ÂI find it >> >> > really hard to believe that you wrote that comment instead of putting in >> >> > the 2 lines of code required for this function. >> >> > >> >> > Especially as-it-is, your code does not work properly and leaks memory >> >> > badly. ÂWhy would you do that on purpose? >> >> >> >> I tried to read some documentation about this. >> >> >> >> 1) driver-mode/device.txt says only that: >> >> > Callback to free the device after all references have >> >> > gone away. This should be set by the allocator of the >> >> > device (i.e. the bus driver that discovered the device). >> >> I *really* do not know how my driver should "free" core on AXI bus. >> > >> > The structure that you have created, added to the bus, is now ready to >> > have its memory freed. ÂSo free it. >> > >> > This usually means something like: >> > Â Â Â Âstruct my_obj = to_my_obj(dev); >> > Â Â Â Âkfree(my_obj); >> > in the release function. >> >> I register core->dev to the bus (I set core->dev.bus and >> core->dev.parent, is that what you mean?). This core->dev is "struct >> dev" embedded in "struct axi_device". By embedded I mean it is *not* a >> pointer, I do not alloc it, it's part of the "struct axi_device". > > That is exactly as it should be. > > Then in your release function, free the struct axi_device. ÂIt's that > simple. ÂTo try to free it before then would be wrong and cause > problems. This is because it is defined as: struct axi_device cores[AXI_MAX_NR_CORES]; >> >> 4) SSB in it's ssb_release_dev just calls kfree on struct that was >> >> allocated when registering drivers. *I do not* allocate such a struct, >> >> so I believe I do exactly the same memory leak as SSB does. >> > >> > Well someone allocated it, right? ÂWho did it? ÂIf it wasn't you, where >> > did that structure come from and why are you registering it on your bus? >> > >> >> Can you spend 2 more minues in addition to commenting my ideas and >> >> help me with writing that 2 lines I missed? Where do I leak memory in >> >> my driver? Which struct should I kfree? >> > >> > The structure that you wrap around 'struct device' for your bus. >> >> As explained above, this I do not dynamically alloc this 'struct >> device'. So is there really any memory leak? > > Yes, no one ever freed your struct axi_device that you created. I agree that defining "cores" as array with maxium possible size instead of linked list eats more memory than needed, but at least it does not leak anything. -- RafaÅ _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
