From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: linux-sgx@vger.kernel.org,
Shay Katz-zamir <shay.katz-zamir@intel.com>,
Serge Ayoun <serge.ayoun@intel.com>
Subject: Re: [PATCH v3 14/17] x86/sgx: Replace section->free_cnt with a global sgx_nr_free_pages
Date: Tue, 17 Sep 2019 15:50:28 -0700 [thread overview]
Message-ID: <20190917225028.GC10319@linux.intel.com> (raw)
In-Reply-To: <20190916101803.30726-15-jarkko.sakkinen@linux.intel.com>
On Mon, Sep 16, 2019 at 01:18:00PM +0300, Jarkko Sakkinen wrote:
> Replace section specific counters with a single gloal counter for free
> pages. In effect, remove sgx_calc_free_cnt().
>
> Cc: Sean Christopherson <sean.j.christopherson@intel.com>
> Cc: Shay Katz-zamir <shay.katz-zamir@intel.com>
> Cc: Serge Ayoun <serge.ayoun@intel.com>
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> ---
> arch/x86/kernel/cpu/sgx/main.c | 11 ++++++-----
> arch/x86/kernel/cpu/sgx/reclaim.c | 19 ++-----------------
> arch/x86/kernel/cpu/sgx/sgx.h | 3 +--
> 3 files changed, 9 insertions(+), 24 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
> index 4c03e5f33414..f37d28023b97 100644
> --- a/arch/x86/kernel/cpu/sgx/main.c
> +++ b/arch/x86/kernel/cpu/sgx/main.c
> @@ -14,19 +14,20 @@
>
> struct sgx_epc_section sgx_epc_sections[SGX_MAX_EPC_SECTIONS];
> int sgx_nr_epc_sections;
> +unsigned long sgx_nr_free_pages;
>
> static struct sgx_epc_page *sgx_section_try_take_page(
> struct sgx_epc_section *section)
> {
> struct sgx_epc_page *page;
>
> - if (!section->free_cnt)
> + if (list_empty(§ion->page_list))
> return NULL;
>
> page = list_first_entry(§ion->page_list, struct sgx_epc_page,
> list);
> list_del_init(&page->list);
> - section->free_cnt--;
> + sgx_nr_free_pages--;
> return page;
> }
>
> @@ -90,7 +91,7 @@ struct sgx_epc_page *sgx_alloc_page(void *owner, bool reclaim)
> schedule();
> }
>
> - if (sgx_calc_free_cnt() < SGX_NR_LOW_PAGES)
> + if (sgx_nr_free_pages < SGX_NR_LOW_PAGES)
> wake_up(&ksgxswapd_waitq);
>
> return entry;
> @@ -136,7 +137,7 @@ int __sgx_free_page(struct sgx_epc_page *page)
>
> spin_lock(§ion->lock);
> list_add_tail(&page->list, §ion->page_list);
> - section->free_cnt++;
> + sgx_nr_free_pages++;
This isn't safe when there are multiple EPC sections as each section has
its own spinlock.
> spin_unlock(§ion->lock);
>
> return 0;
> @@ -202,7 +203,7 @@ static __init int sgx_init_epc_section(u64 addr, u64 size, unsigned long index,
> goto out;
> page->desc = (addr + (i << PAGE_SHIFT)) | index;
> list_add_tail(&page->list, §ion->unsanitized_page_list);
> - section->free_cnt++;
> + sgx_nr_free_pages++;
> }
>
> return 0;
> diff --git a/arch/x86/kernel/cpu/sgx/reclaim.c b/arch/x86/kernel/cpu/sgx/reclaim.c
> index cc3155b61513..2e04a923d8dc 100644
> --- a/arch/x86/kernel/cpu/sgx/reclaim.c
> +++ b/arch/x86/kernel/cpu/sgx/reclaim.c
> @@ -64,7 +64,7 @@ static void sgx_sanitize_section(struct sgx_epc_section *section)
>
> static inline bool sgx_should_reclaim(void)
> {
> - return sgx_calc_free_cnt() < SGX_NR_HIGH_PAGES &&
> + return sgx_nr_free_pages < SGX_NR_HIGH_PAGES &&
> !list_empty(&sgx_active_page_list);
> }
>
> @@ -432,7 +432,6 @@ void sgx_reclaim_pages(void)
> if (!epc_page)
> continue;
>
> -
> encl_page = epc_page->owner;
> sgx_reclaimer_write(epc_page);
> kref_put(&encl_page->encl->refcount, sgx_encl_release);
> @@ -441,21 +440,7 @@ void sgx_reclaim_pages(void)
> section = sgx_epc_section(epc_page);
> spin_lock(§ion->lock);
> list_add_tail(&epc_page->list, §ion->page_list);
> - section->free_cnt++;
> + sgx_nr_free_pages++;
> spin_unlock(§ion->lock);
> }
> }
> -
> -unsigned long sgx_calc_free_cnt(void)
> -{
> - struct sgx_epc_section *section;
> - unsigned long free_cnt = 0;
> - int i;
> -
> - for (i = 0; i < sgx_nr_epc_sections; i++) {
> - section = &sgx_epc_sections[i];
> - free_cnt += section->free_cnt;
> - }
> -
> - return free_cnt;
> -}
> diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h
> index 9b08690262b5..56d0bde3f4d8 100644
> --- a/arch/x86/kernel/cpu/sgx/sgx.h
> +++ b/arch/x86/kernel/cpu/sgx/sgx.h
> @@ -30,7 +30,6 @@ struct sgx_epc_section {
> void *va;
> struct list_head page_list;
> struct list_head unsanitized_page_list;
> - unsigned long free_cnt;
> spinlock_t lock;
> };
>
> @@ -72,6 +71,7 @@ static inline void *sgx_epc_addr(struct sgx_epc_page *page)
> #define SGX_NR_HIGH_PAGES 64
>
> extern int sgx_nr_epc_sections;
> +extern unsigned long sgx_nr_free_pages;
> extern struct task_struct *ksgxswapd_tsk;
> extern struct wait_queue_head(ksgxswapd_waitq);
> extern struct list_head sgx_active_page_list;
> @@ -79,7 +79,6 @@ extern spinlock_t sgx_active_page_list_lock;
>
> int sgx_page_reclaimer_init(void);
> void sgx_mark_page_reclaimable(struct sgx_epc_page *page);
> -unsigned long sgx_calc_free_cnt(void);
> void sgx_reclaim_pages(void);
>
> struct sgx_epc_page *sgx_alloc_page(void *owner, bool reclaim);
> --
> 2.20.1
>
next prev parent reply other threads:[~2019-09-17 22:50 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-16 10:17 [PATCH v3 00/17] Fixes and updates for v23 Jarkko Sakkinen
2019-09-16 10:17 ` [PATCH v3 01/17] selftest/x86/sgx: Remove encl_piggy.h Jarkko Sakkinen
2019-09-16 10:17 ` [PATCH v3 02/17] x86/sgx: Clean up internal includes Jarkko Sakkinen
2019-09-16 10:17 ` [PATCH v3 03/17] x86/sgx: Write backing storage only if EWB is successful Jarkko Sakkinen
2019-09-16 10:17 ` [PATCH v3 04/17] x86/sgx: Rename 'j' as 'cnt' in sgx_reclaim_pages() Jarkko Sakkinen
2019-09-16 10:17 ` [PATCH v3 05/17] x86/sgx: Turn encls_failed() as inline function Jarkko Sakkinen
2019-09-16 10:17 ` [PATCH v3 06/17] x86/sgx: Move sgx_einit() to encls.c Jarkko Sakkinen
2019-09-16 10:17 ` [PATCH v3 07/17] x86/sgx: Remove pages in sgx_reclaimer_write() Jarkko Sakkinen
2019-09-16 10:17 ` [PATCH v3 08/17] x86/sgx: Calculate page index " Jarkko Sakkinen
2019-09-16 10:17 ` [PATCH v3 09/17] x86/sgx: Move SGX_ENCL_DEAD check to sgx_reclaimer_write() Jarkko Sakkinen
2019-09-17 23:13 ` Sean Christopherson
2019-09-18 4:15 ` Jarkko Sakkinen
2019-09-17 23:21 ` Sean Christopherson
2019-09-18 4:16 ` Jarkko Sakkinen
2019-09-16 10:17 ` [PATCH v3 10/17] x86/sgx: Free VA slot when the EWB flow fails Jarkko Sakkinen
2019-09-16 10:17 ` [PATCH v3 11/17] x86/sgx: Call sgx_encl_destroy() " Jarkko Sakkinen
2019-09-16 10:17 ` [PATCH v3 12/17] x86/sgx: Open code sgx_reclaimer_get() and sgx_reclaimer_put() Jarkko Sakkinen
2019-09-17 23:07 ` Sean Christopherson
2019-09-18 4:12 ` Jarkko Sakkinen
2019-09-20 13:38 ` Jarkko Sakkinen
2019-09-16 10:17 ` [PATCH v3 13/17] x86/sgx: Introduce sgx_can_reclaim() Jarkko Sakkinen
2019-09-17 23:25 ` Sean Christopherson
2019-09-25 18:28 ` Sean Christopherson
2019-09-27 15:33 ` Jarkko Sakkinen
2019-09-16 10:18 ` [PATCH v3 14/17] x86/sgx: Replace section->free_cnt with a global sgx_nr_free_pages Jarkko Sakkinen
2019-09-17 22:50 ` Sean Christopherson [this message]
2019-09-18 4:07 ` Jarkko Sakkinen
2019-09-16 10:18 ` [PATCH v3 15/17] x86/sgx: sgx_vma_access(): Do not return -ECANCELED on invalid TCS pages Jarkko Sakkinen
2019-09-16 10:18 ` [PATCH v3 16/17] x86/sgx: Introduce sgx_encl_get_backing() Jarkko Sakkinen
2019-09-17 23:05 ` Sean Christopherson
2019-09-18 4:10 ` Jarkko Sakkinen
2019-09-16 10:18 ` [PATCH v3 17/17] x86/sgx: Fix pages in the BLOCKED state ending up to the free pool Jarkko Sakkinen
2019-09-17 23:34 ` Sean Christopherson
2019-09-18 4:21 ` Jarkko Sakkinen
2019-09-25 0:27 ` Jarkko Sakkinen
2019-09-25 18:33 ` Sean Christopherson
2019-09-27 15:39 ` Jarkko Sakkinen
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