On Sat, May 27, 2023 at 8:07 AM Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote: > > On Fri, May 26, 2023 at 09:13:05PM -0700, Yosry Ahmed wrote: > > On Fri, May 26, 2023 at 9:01 PM Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote: > > > > > > On Sat, May 27, 2023 at 06:31:26PM +0800, Miaohe Lin wrote: > > > > The function mem_cgroup_from_obj() is not used anymore. Remove it and > > > > clean up relevant comments. > > > > > > You should have looked at the git history to see why it was created > > > and who used it. > > > > > > Shakeel, Vasily, are you going to retry adding commit 1d0403d20f6c? > > > > That commit did not introduce the function though, no? It was > > introduced before it and replaced by other variants over time (like > > mem_cgroup_from_slab_obj()). It looks like that commit was reverted ~9 > > months ago. We can always bring it back if/when needed. > > The commit immediately preceding it is fc4db90fe71e. > > Of course we can bring it back. It's just code. But avoiding > unnecessary churn is also good. Let's wait to hear from Vasily. > > > It also looks to me that 1d0403d20f6c was using mem_cgroup_from_obj() > > on a struct net object, which is allocated in net_alloc() from a slab > > cache, so mem_cgroup_from_slab_obj() should be sufficient, no? > > Clearly not. I dived deeper into the history on LKML, and you are right: https://lore.kernel.org/all/Yp4F6n2Ie32re7Ed@qian/ I still do not understand why mem_cgroup_from_slab_obj() would not be sufficient, so I am hoping Vasily or Shakeel can help me understand here. Seems to be something arch-specific. Thanks for digging this up, Matthew.
