On Tue Jan 30, 2024 at 4:09 AM EET, Haitao Huang wrote: > From: Sean Christopherson <[email protected]> > > Introduce a data structure to wrap the existing reclaimable list and its > spinlock. Each cgroup later will have one instance of this structure to > track EPC pages allocated for processes associated with the same cgroup. > Just like the global SGX reclaimer (ksgxd), an EPC cgroup reclaims pages > from the reclaimable list in this structure when its usage reaches near > its limit. > > Use this structure to encapsulate the LRU list and its lock used by the > global reclaimer. > > Signed-off-by: Sean Christopherson <[email protected]> > Co-developed-by: Kristen Carlson Accardi <[email protected]> > Signed-off-by: Kristen Carlson Accardi <[email protected]> > Co-developed-by: Haitao Huang <[email protected]> > Signed-off-by: Haitao Huang <[email protected]>
I'd put author as last sob but that said I'm not sure if there is rigid rule to do so. Thus not saying must here. > Cc: Sean Christopherson <[email protected]> > --- > V6: > - removed introduction to unreclaimables in commit message. > > V4: > - Removed unneeded comments for the spinlock and the non-reclaimables. > (Kai, Jarkko) > - Revised the commit to add introduction comments for unreclaimables and > multiple LRU lists.(Kai) > - Reordered the patches: delay all changes for unreclaimables to > later, and this one becomes the first change in the SGX subsystem. > > V3: > - Removed the helper functions and revised commit messages. > --- > arch/x86/kernel/cpu/sgx/main.c | 39 +++++++++++++++++----------------- > arch/x86/kernel/cpu/sgx/sgx.h | 15 +++++++++++++ > 2 files changed, 35 insertions(+), 19 deletions(-) > > diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c > index c32f18b70c73..912959c7ecc9 100644 > --- a/arch/x86/kernel/cpu/sgx/main.c > +++ b/arch/x86/kernel/cpu/sgx/main.c > @@ -28,10 +28,9 @@ static DEFINE_XARRAY(sgx_epc_address_space); > > /* > * These variables are part of the state of the reclaimer, and must be > accessed > - * with sgx_reclaimer_lock acquired. > + * with sgx_global_lru.lock acquired. > */ > -static LIST_HEAD(sgx_active_page_list); > -static DEFINE_SPINLOCK(sgx_reclaimer_lock); > +static struct sgx_epc_lru_list sgx_global_lru; > > static atomic_long_t sgx_nr_free_pages = ATOMIC_LONG_INIT(0); > > @@ -306,13 +305,13 @@ static void sgx_reclaim_pages(void) > int ret; > int i; > > - spin_lock(&sgx_reclaimer_lock); > + spin_lock(&sgx_global_lru.lock); > for (i = 0; i < SGX_NR_TO_SCAN; i++) { > - if (list_empty(&sgx_active_page_list)) > + epc_page = list_first_entry_or_null(&sgx_global_lru.reclaimable, > + struct sgx_epc_page, list); > + if (!epc_page) > break; > > - epc_page = list_first_entry(&sgx_active_page_list, > - struct sgx_epc_page, list); > list_del_init(&epc_page->list); > encl_page = epc_page->owner; > > @@ -324,7 +323,7 @@ static void sgx_reclaim_pages(void) > */ > epc_page->flags &= ~SGX_EPC_PAGE_RECLAIMER_TRACKED; > } > - spin_unlock(&sgx_reclaimer_lock); > + spin_unlock(&sgx_global_lru.lock); > > for (i = 0; i < cnt; i++) { > epc_page = chunk[i]; > @@ -347,9 +346,9 @@ static void sgx_reclaim_pages(void) > continue; > > skip: > - spin_lock(&sgx_reclaimer_lock); > - list_add_tail(&epc_page->list, &sgx_active_page_list); > - spin_unlock(&sgx_reclaimer_lock); > + spin_lock(&sgx_global_lru.lock); > + list_add_tail(&epc_page->list, &sgx_global_lru.reclaimable); > + spin_unlock(&sgx_global_lru.lock); > > kref_put(&encl_page->encl->refcount, sgx_encl_release); > > @@ -380,7 +379,7 @@ static void sgx_reclaim_pages(void) > static bool sgx_should_reclaim(unsigned long watermark) > { > return atomic_long_read(&sgx_nr_free_pages) < watermark && > - !list_empty(&sgx_active_page_list); > + !list_empty(&sgx_global_lru.reclaimable); > } > > /* > @@ -432,6 +431,8 @@ static bool __init sgx_page_reclaimer_init(void) > > ksgxd_tsk = tsk; > > + sgx_lru_init(&sgx_global_lru); > + > return true; > } > > @@ -507,10 +508,10 @@ struct sgx_epc_page *__sgx_alloc_epc_page(void) > */ > void sgx_mark_page_reclaimable(struct sgx_epc_page *page) > { > - spin_lock(&sgx_reclaimer_lock); > + spin_lock(&sgx_global_lru.lock); > page->flags |= SGX_EPC_PAGE_RECLAIMER_TRACKED; > - list_add_tail(&page->list, &sgx_active_page_list); > - spin_unlock(&sgx_reclaimer_lock); > + list_add_tail(&page->list, &sgx_global_lru.reclaimable); > + spin_unlock(&sgx_global_lru.lock); > } > > /** > @@ -525,18 +526,18 @@ void sgx_mark_page_reclaimable(struct sgx_epc_page > *page) > */ > int sgx_unmark_page_reclaimable(struct sgx_epc_page *page) > { > - spin_lock(&sgx_reclaimer_lock); > + spin_lock(&sgx_global_lru.lock); > if (page->flags & SGX_EPC_PAGE_RECLAIMER_TRACKED) { > /* The page is being reclaimed. */ > if (list_empty(&page->list)) { > - spin_unlock(&sgx_reclaimer_lock); > + spin_unlock(&sgx_global_lru.lock); > return -EBUSY; > } > > list_del(&page->list); > page->flags &= ~SGX_EPC_PAGE_RECLAIMER_TRACKED; > } > - spin_unlock(&sgx_reclaimer_lock); > + spin_unlock(&sgx_global_lru.lock); > > return 0; > } > @@ -578,7 +579,7 @@ struct sgx_epc_page *sgx_alloc_epc_page(void *owner, bool > reclaim) > break; > } > > - if (list_empty(&sgx_active_page_list)) { > + if (list_empty(&sgx_global_lru.reclaimable)) { > page = ERR_PTR(-ENOMEM); > break; > } > diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h > index a898d86dead0..0e99e9ae3a67 100644 > --- a/arch/x86/kernel/cpu/sgx/sgx.h > +++ b/arch/x86/kernel/cpu/sgx/sgx.h > @@ -88,6 +88,21 @@ static inline void *sgx_get_epc_virt_addr(struct > sgx_epc_page *page) > return section->virt_addr + index * PAGE_SIZE; > } > > +/* > + * Contains EPC pages tracked by the global reclaimer (ksgxd) or an EPC > + * cgroup. > + */ > +struct sgx_epc_lru_list { > + spinlock_t lock; > + struct list_head reclaimable; > +}; > + > +static inline void sgx_lru_init(struct sgx_epc_lru_list *lru) > +{ > + spin_lock_init(&lru->lock); > + INIT_LIST_HEAD(&lru->reclaimable); > +} > + > struct sgx_epc_page *__sgx_alloc_epc_page(void); > void sgx_free_epc_page(struct sgx_epc_page *page); > Reviewed-by: Jarkko Sakkinen <[email protected]> BR, Jarkko
