From mboxrd@z Thu Jan 1 00:00:00 1970 From: Haitao Huang Subject: [PATCH v4 08/18] x86/sgx: Use a list to track to-be-reclaimed pages Date: Tue, 12 Sep 2023 21:06:25 -0700 Message-ID: <20230913040635.28815-9-haitao.huang@linux.intel.com> References: <20230913040635.28815-1-haitao.huang@linux.intel.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1694578132; x=1726114132; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=2PsYQ63FO9gKjJV2WD5fndgBtRRQxs63BhKeT1YL4QI=; b=Y+aA71W8qFfmCh7THPvt56RUyK9R+QNcGbbLMp2LO4Z0VnazN6mcjxcJ A+rvrymFhg0cZZCom8gVEw6yfsZpty04jou8+blf2KuL9lsvdcbUt7a1z bcDJTciO7Oux8OZVUExY7tPqf5gPiFmX7Z+mwlUaorN1Ypz52nj7ZEHam Hfn/H0ROV9G4rh9MsoqG1u1PjKs3kvjqjegG3vcvH2r7Lb/8ASrUHCs9K TMuc6CIf6HiBoElOID5qSNCx7U838IFoD4GdXVCMTSlmcmIGNmnd3TS5U uDFvou0WJCnuhjSQRC23Sme3Z+LjZ+vEFv0h1myPDgd13zUBeaVeyJm9f A==; In-Reply-To: <20230913040635.28815-1-haitao.huang-VuQAYsv1563Yd54FQh9/CA@public.gmane.org> List-ID: Content-Type: text/plain; charset="us-ascii" To: jarkko-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, dave.hansen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org, tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-sgx-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org, mingo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, bp-Gina5bIWoIWzQB+pC5nmwQ@public.gmane.org, hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org, sohil.mehta-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org Cc: zhiquan1.li-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, kristen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org, seanjc-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, zhanb-0li6OtcxBFHby3iVrkZq2A@public.gmane.org, anakrish-0li6OtcxBFHby3iVrkZq2A@public.gmane.org, mikko.ylinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org, yangjie-0li6OtcxBFHby3iVrkZq2A@public.gmane.org From: Kristen Carlson Accardi 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 Signed-off-by: Kristen Carlson Accardi Signed-off-by: Haitao Huang Cc: Sean Christopherson --- V4: - Changes needed for patch reordering - Revised commit message V3: - Removed list wrappers --- arch/x86/kernel/cpu/sgx/main.c | 40 +++++++++++++++------------------- 1 file changed, 18 insertions(+), 22 deletions(-) diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index c1ae19a154d0..fba06dc5abfe 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -293,12 +293,11 @@ 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; @@ -314,18 +313,22 @@ 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. + /* The owner is freeing the page, remove it from the + * LRU list */ sgx_epc_page_reset_state(epc_page); + list_del_init(&epc_page->list); } } 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)) @@ -340,6 +343,7 @@ static void sgx_reclaim_pages(void) goto skip; } + i++; encl_page->desc |= SGX_ENCL_PAGE_BEING_RECLAIMED; mutex_unlock(&encl_page->encl->lock); continue; @@ -347,27 +351,19 @@ 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); -- 2.25.1