On Mon Feb 5, 2024 at 11:06 PM EET, Haitao Huang wrote: > From: Kristen Carlson Accardi <kristen@xxxxxxxxxxxxxxx> > > Implement the reclamation flow for cgroup, encapsulated in the top-level > function sgx_epc_cgroup_reclaim_pages(). It does a pre-order walk on its > subtree, and make calls to sgx_reclaim_pages() at each node passing in > the LRU of that node. It keeps track of total reclaimed pages, and pages > left to attempt. It stops the walk if desired number of pages are > attempted. > > In some contexts, e.g. page fault handling, only asynchronous > reclamation is allowed. Create a work-queue, corresponding work item and > function definitions to support the asynchronous reclamation. Both > synchronous and asynchronous flows invoke the same top level reclaim > function, and will be triggered later by sgx_epc_cgroup_try_charge() > when usage of the cgroup is at or near its limit. > > Co-developed-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> > Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> > Signed-off-by: Kristen Carlson Accardi <kristen@xxxxxxxxxxxxxxx> > Co-developed-by: Haitao Huang <haitao.huang@xxxxxxxxxxxxxxx> > Signed-off-by: Haitao Huang <haitao.huang@xxxxxxxxxxxxxxx> > --- > V9: > - Add comments for static variables. (Jarkko) > > V8: > - Remove alignment for substructure variables. (Jarkko) > > V7: > - Split this out from the big patch, #10 in V6. (Dave, Kai) > --- > arch/x86/kernel/cpu/sgx/epc_cgroup.c | 181 ++++++++++++++++++++++++++- > arch/x86/kernel/cpu/sgx/epc_cgroup.h | 3 + > 2 files changed, 183 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kernel/cpu/sgx/epc_cgroup.c b/arch/x86/kernel/cpu/sgx/epc_cgroup.c > index f4a37ace67d7..16b6d9f909eb 100644 > --- a/arch/x86/kernel/cpu/sgx/epc_cgroup.c > +++ b/arch/x86/kernel/cpu/sgx/epc_cgroup.c > @@ -8,9 +8,180 @@ > /* The root EPC cgroup */ > static struct sgx_epc_cgroup epc_cg_root; > > +/* > + * The work queue that reclaims EPC pages in the background for cgroups. > + * > + * A cgroup schedules a work item into this queue to reclaim pages within the > + * same cgroup when its usage limit is reached and synchronous reclamation is not > + * an option, e.g., in a fault handler. > + */ Here I get a bit confused of the text because of "e.g., in a fault handler". Can we enumerate sites broadly where stimulus could happen. Does not have to be complete but at least the most common locations would make this comment *actually* useful for later maintenance. BR, Jarkko
