| Message ID | 20231030182013.40086-9-haitao.huang@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add Cgroup support for SGX EPC memory | expand |
On Mon Oct 30, 2023 at 8:20 PM EET, Haitao Huang wrote: > From: Sean Christopherson <sean.j.christopherson@intel.com> > > Change sgx_reclaim_pages() to use a list rather than an array for > storing the epc_pages which will be reclaimed. This change is needed > to transition to the LRU implementation for EPC cgroup support. > > When the EPC cgroup is implemented, the reclaiming process will do a > pre-order tree walk for the subtree starting from the limit-violating > cgroup. When each node is visited, candidate pages are selected from > its "reclaimable" LRU list and moved into this temporary list. Passing a > list from node to node for temporary storage in this walk is more > straightforward than using an array. > > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > Co-developed-by: Kristen Carlson Accardi <kristen@linux.intel.com> > Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com> > Co-developed-by: Haitao Huang<haitao.huang@linux.intel.com> > Signed-off-by: Haitao Huang<haitao.huang@linux.intel.com> > Cc: Sean Christopherson <seanjc@google.com> > --- > V6: > - Remove extra list_del_init and style fix (Kai) > > V4: > - Changes needed for patch reordering > - Revised commit message > > V3: > - Removed list wrappers > --- > arch/x86/kernel/cpu/sgx/main.c | 35 +++++++++++++++------------------- > 1 file changed, 15 insertions(+), 20 deletions(-) > > diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c > index e27ac73d8843..33bcba313d40 100644 > --- a/arch/x86/kernel/cpu/sgx/main.c > +++ b/arch/x86/kernel/cpu/sgx/main.c > @@ -296,12 +296,11 @@ static void sgx_reclaimer_write(struct sgx_epc_page *epc_page, > */ > static void sgx_reclaim_pages(void) > { > - struct sgx_epc_page *chunk[SGX_NR_TO_SCAN]; > struct sgx_backing backing[SGX_NR_TO_SCAN]; > + struct sgx_epc_page *epc_page, *tmp; > struct sgx_encl_page *encl_page; > - struct sgx_epc_page *epc_page; > pgoff_t page_index; > - int cnt = 0; > + LIST_HEAD(iso); > int ret; > int i; > > @@ -317,7 +316,7 @@ static void sgx_reclaim_pages(void) > > if (kref_get_unless_zero(&encl_page->encl->refcount) != 0) { > sgx_epc_page_set_state(epc_page, SGX_EPC_PAGE_RECLAIM_IN_PROGRESS); > - chunk[cnt++] = epc_page; > + list_move_tail(&epc_page->list, &iso); > } else > /* The owner is freeing the page. No need to add the > * page back to the list of reclaimable pages. > @@ -326,8 +325,11 @@ static void sgx_reclaim_pages(void) > } > spin_unlock(&sgx_global_lru.lock); > > - for (i = 0; i < cnt; i++) { > - epc_page = chunk[i]; > + if (list_empty(&iso)) > + return; > + > + i = 0; > + list_for_each_entry_safe(epc_page, tmp, &iso, list) { > encl_page = epc_page->owner; > > if (!sgx_reclaimer_age(epc_page)) > @@ -342,6 +344,7 @@ static void sgx_reclaim_pages(void) > goto skip; > } > > + i++; > encl_page->desc |= SGX_ENCL_PAGE_BEING_RECLAIMED; > mutex_unlock(&encl_page->encl->lock); > continue; > @@ -349,27 +352,19 @@ static void sgx_reclaim_pages(void) > skip: > spin_lock(&sgx_global_lru.lock); > sgx_epc_page_set_state(epc_page, SGX_EPC_PAGE_RECLAIMABLE); > - list_add_tail(&epc_page->list, &sgx_global_lru.reclaimable); > + list_move_tail(&epc_page->list, &sgx_global_lru.reclaimable); > spin_unlock(&sgx_global_lru.lock); > > kref_put(&encl_page->encl->refcount, sgx_encl_release); > - > - chunk[i] = NULL; > - } > - > - for (i = 0; i < cnt; i++) { > - epc_page = chunk[i]; > - if (epc_page) > - sgx_reclaimer_block(epc_page); > } > > - for (i = 0; i < cnt; i++) { > - epc_page = chunk[i]; > - if (!epc_page) > - continue; > + list_for_each_entry(epc_page, &iso, list) > + sgx_reclaimer_block(epc_page); > > + i = 0; > + list_for_each_entry_safe(epc_page, tmp, &iso, list) { > encl_page = epc_page->owner; > - sgx_reclaimer_write(epc_page, &backing[i]); > + sgx_reclaimer_write(epc_page, &backing[i++]); Couldn't you alternatively "&backing[--i]" and not reset i to zero before the loop? > > kref_put(&encl_page->encl->refcount, sgx_encl_release); > sgx_epc_page_reset_state(epc_page); BR, Jarkko
diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index e27ac73d8843..33bcba313d40 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -296,12 +296,11 @@ static void sgx_reclaimer_write(struct sgx_epc_page *epc_page, */ static void sgx_reclaim_pages(void) { - struct sgx_epc_page *chunk[SGX_NR_TO_SCAN]; struct sgx_backing backing[SGX_NR_TO_SCAN]; + struct sgx_epc_page *epc_page, *tmp; struct sgx_encl_page *encl_page; - struct sgx_epc_page *epc_page; pgoff_t page_index; - int cnt = 0; + LIST_HEAD(iso); int ret; int i; @@ -317,7 +316,7 @@ static void sgx_reclaim_pages(void) if (kref_get_unless_zero(&encl_page->encl->refcount) != 0) { sgx_epc_page_set_state(epc_page, SGX_EPC_PAGE_RECLAIM_IN_PROGRESS); - chunk[cnt++] = epc_page; + list_move_tail(&epc_page->list, &iso); } else /* The owner is freeing the page. No need to add the * page back to the list of reclaimable pages. @@ -326,8 +325,11 @@ static void sgx_reclaim_pages(void) } spin_unlock(&sgx_global_lru.lock); - for (i = 0; i < cnt; i++) { - epc_page = chunk[i]; + if (list_empty(&iso)) + return; + + i = 0; + list_for_each_entry_safe(epc_page, tmp, &iso, list) { encl_page = epc_page->owner; if (!sgx_reclaimer_age(epc_page)) @@ -342,6 +344,7 @@ static void sgx_reclaim_pages(void) goto skip; } + i++; encl_page->desc |= SGX_ENCL_PAGE_BEING_RECLAIMED; mutex_unlock(&encl_page->encl->lock); continue; @@ -349,27 +352,19 @@ static void sgx_reclaim_pages(void) skip: spin_lock(&sgx_global_lru.lock); sgx_epc_page_set_state(epc_page, SGX_EPC_PAGE_RECLAIMABLE); - list_add_tail(&epc_page->list, &sgx_global_lru.reclaimable); + list_move_tail(&epc_page->list, &sgx_global_lru.reclaimable); spin_unlock(&sgx_global_lru.lock); kref_put(&encl_page->encl->refcount, sgx_encl_release); - - chunk[i] = NULL; - } - - for (i = 0; i < cnt; i++) { - epc_page = chunk[i]; - if (epc_page) - sgx_reclaimer_block(epc_page); } - for (i = 0; i < cnt; i++) { - epc_page = chunk[i]; - if (!epc_page) - continue; + list_for_each_entry(epc_page, &iso, list) + sgx_reclaimer_block(epc_page); + i = 0; + list_for_each_entry_safe(epc_page, tmp, &iso, list) { encl_page = epc_page->owner; - sgx_reclaimer_write(epc_page, &backing[i]); + sgx_reclaimer_write(epc_page, &backing[i++]); kref_put(&encl_page->encl->refcount, sgx_encl_release); sgx_epc_page_reset_state(epc_page);