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* [PATCH v3 0/3] Allow tmem to be disabled via Kconfig
@ 2016-03-16 14:10 Doug Goldstein
  2016-03-16 14:10 ` [PATCH v3 1/3] tmem: add tmem_disable() function Doug Goldstein
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: Doug Goldstein @ 2016-03-16 14:10 UTC (permalink / raw)
  To: xen-devel; +Cc: Doug Goldstein

Allows expert users to disable tmem  via Kconfig. Incorporates feedback
from Jan and Konrad. Patch 2 & 3 from v1 were merged and patch 4 was
dropped.

Doug Goldstein (3):
  tmem: add tmem_disable() function
  tmem: drop direct usage of opt_tmem
  tmem: allow tmem to be disabled with Kconfig

 xen/arch/x86/setup.c               |  6 +++---
 xen/arch/x86/x86_64/compat/entry.S |  4 ++++
 xen/arch/x86/x86_64/entry.S        |  4 ++++
 xen/common/Kconfig                 | 10 ++++++++++
 xen/common/Makefile                |  8 +++++---
 xen/common/memory.c                |  2 +-
 xen/common/page_alloc.c            |  8 ++++----
 xen/common/tmem.c                  |  3 +++
 xen/include/xen/hypercall.h        |  4 ++++
 xen/include/xen/tmem.h             | 26 ++++++++++++++++++++++++++
 xen/include/xen/tmem_xen.h         | 16 ++++++++++++++++
 11 files changed, 80 insertions(+), 11 deletions(-)

-- 
2.4.10


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^ permalink raw reply	[flat|nested] 4+ messages in thread
* [PATCH v3 1/3] tmem: add tmem_disable() function
  2016-03-16 14:10 [PATCH v3 0/3] Allow tmem to be disabled via Kconfig Doug Goldstein
@ 2016-03-16 14:10 ` Doug Goldstein
  2016-03-16 14:11 ` [PATCH v3 2/3] tmem: drop direct usage of opt_tmem Doug Goldstein
  2016-03-16 14:11 ` [PATCH v3 3/3] tmem: allow tmem to be disabled with Kconfig Doug Goldstein
  2 siblings, 0 replies; 4+ messages in thread
From: Doug Goldstein @ 2016-03-16 14:10 UTC (permalink / raw)
  To: xen-devel; +Cc: Keir Fraser, Doug Goldstein, Jan Beulich, Andrew Cooper

Instead of manipulating the opt_tmem variable directly utilize a wrapper
function.

Signed-off-by: Doug Goldstein <cardoe@cardoe.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
---
CC: Keir Fraser <keir@xen.org>
CC: Jan Beulich <jbeulich@suse.com>
CC: Andrew Cooper <andrew.cooper3@citrix.com>
CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

change since v2:
- none
change since v1:
- none
---
 xen/arch/x86/setup.c       | 4 ++--
 xen/include/xen/tmem_xen.h | 5 +++++
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index a8bf2c9..5011930 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -25,7 +25,7 @@
 #include <xen/dmi.h>
 #include <xen/pfn.h>
 #include <xen/nodemask.h>
-#include <xen/tmem_xen.h> /* for opt_tmem only */
+#include <xen/tmem_xen.h>
 #include <xen/watchdog.h>
 #include <public/version.h>
 #include <compat/platform.h>
@@ -1276,7 +1276,7 @@ void __init noreturn __start_xen(unsigned long mbi_p)
         {
            printk(XENLOG_WARNING
                   "TMEM physical RAM limit exceeded, disabling TMEM\n");
-           opt_tmem = 0;
+           tmem_disable();
         }
     }
     else
diff --git a/xen/include/xen/tmem_xen.h b/xen/include/xen/tmem_xen.h
index c770f3e..f516bbe 100644
--- a/xen/include/xen/tmem_xen.h
+++ b/xen/include/xen/tmem_xen.h
@@ -69,6 +69,11 @@ static inline bool_t tmem_enabled(void)
     return opt_tmem;
 }
 
+static inline void tmem_disable(void)
+{
+    opt_tmem = 0;
+}
+
 /*
  * Memory free page list management
  */
-- 
2.4.10


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^ permalink raw reply related	[flat|nested] 4+ messages in thread
* [PATCH v3 2/3] tmem: drop direct usage of opt_tmem
  2016-03-16 14:10 [PATCH v3 0/3] Allow tmem to be disabled via Kconfig Doug Goldstein
  2016-03-16 14:10 ` [PATCH v3 1/3] tmem: add tmem_disable() function Doug Goldstein
@ 2016-03-16 14:11 ` Doug Goldstein
  2016-03-16 14:11 ` [PATCH v3 3/3] tmem: allow tmem to be disabled with Kconfig Doug Goldstein
  2 siblings, 0 replies; 4+ messages in thread
From: Doug Goldstein @ 2016-03-16 14:11 UTC (permalink / raw)
  To: xen-devel; +Cc: Keir Fraser, Doug Goldstein, Jan Beulich, Andrew Cooper

Most callers of tmem_freeable_pages() checked to see if by checking
opt_tmem before calling tmem_freeable_pages() but not all of them did. This
seemed like an oversight and to avoid similar situations like that,
stick the check of tmem into tmem_freeable_pages(). Similarly other
places should not directly check opt_tmem but instead use the
tmem_enabled() helper function.

Signed-off-by: Doug Goldstein <cardoe@cardoe.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
---
CC: Keir Fraser <keir@xen.org>
CC: Jan Beulich <jbeulich@suse.com>
CC: Andrew Cooper <andrew.cooper3@citrix.com>
CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

change since v2:
- merged commit message from patch 2 and 3
change since v1:
- merged patch 2 and 3
---
 xen/arch/x86/setup.c    | 2 +-
 xen/common/memory.c     | 2 +-
 xen/common/page_alloc.c | 8 ++++----
 xen/common/tmem.c       | 3 +++
 4 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index 5011930..c5c332d 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -1272,7 +1272,7 @@ void __init noreturn __start_xen(unsigned long mbi_p)
             init_domheap_pages(s, e);
         }
 
-        if ( opt_tmem )
+        if ( tmem_enabled() )
         {
            printk(XENLOG_WARNING
                   "TMEM physical RAM limit exceeded, disabling TMEM\n");
diff --git a/xen/common/memory.c b/xen/common/memory.c
index ef57219..c7fca96 100644
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -202,7 +202,7 @@ static void populate_physmap(struct memop_args *a)
 
                 if ( unlikely(!page) )
                 {
-                    if ( !opt_tmem || a->extent_order )
+                    if ( !tmem_enabled() || a->extent_order )
                         gdprintk(XENLOG_INFO,
                                  "Could not allocate order=%u extent: id=%d memflags=%#x (%u of %u)\n",
                                  a->extent_order, d->domain_id, a->memflags,
diff --git a/xen/common/page_alloc.c b/xen/common/page_alloc.c
index 22e8feb..98e30e5 100644
--- a/xen/common/page_alloc.c
+++ b/xen/common/page_alloc.c
@@ -652,7 +652,7 @@ static void __init setup_low_mem_virq(void)
 static void check_low_mem_virq(void)
 {
     unsigned long avail_pages = total_avail_pages +
-        (opt_tmem ? tmem_freeable_pages() : 0) - outstanding_claims;
+        tmem_freeable_pages() - outstanding_claims;
 
     if ( unlikely(avail_pages <= low_mem_virq_th) )
     {
@@ -738,7 +738,7 @@ static struct page_info *alloc_heap_pages(
      * Others try tmem pools then fail.  This is a workaround until all
      * post-dom0-creation-multi-page allocations can be eliminated.
      */
-    if ( opt_tmem && ((order == 0) || (order >= 9)) &&
+    if ( ((order == 0) || (order >= 9)) &&
          (total_avail_pages <= midsize_alloc_zone_pages) &&
          tmem_freeable_pages() )
         goto try_tmem;
@@ -984,7 +984,7 @@ static void free_heap_pages(
     avail[node][zone] += 1 << order;
     total_avail_pages += 1 << order;
 
-    if ( opt_tmem )
+    if ( tmem_enabled() )
         midsize_alloc_zone_pages = max(
             midsize_alloc_zone_pages, total_avail_pages / MIDSIZE_ALLOC_FRAC);
 
@@ -1755,7 +1755,7 @@ int assign_pages(
     {
         if ( unlikely((d->tot_pages + (1 << order)) > d->max_pages) )
         {
-            if ( !opt_tmem || order != 0 || d->tot_pages != d->max_pages )
+            if ( !tmem_enabled() || order != 0 || d->tot_pages != d->max_pages )
                 gprintk(XENLOG_INFO, "Over-allocation for domain %u: "
                         "%u > %u\n", d->domain_id,
                         d->tot_pages + (1 << order), d->max_pages);
diff --git a/xen/common/tmem.c b/xen/common/tmem.c
index 0436e49..16e249a 100644
--- a/xen/common/tmem.c
+++ b/xen/common/tmem.c
@@ -2837,6 +2837,9 @@ void *tmem_relinquish_pages(unsigned int order, unsigned int memflags)
 
 unsigned long tmem_freeable_pages(void)
 {
+    if ( !tmem_enabled() )
+        return 0;
+
     return tmem_page_list_pages + _atomic_read(freeable_page_count);
 }
 
-- 
2.4.10


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^ permalink raw reply related	[flat|nested] 4+ messages in thread
* [PATCH v3 3/3] tmem: allow tmem to be disabled with Kconfig
  2016-03-16 14:10 [PATCH v3 0/3] Allow tmem to be disabled via Kconfig Doug Goldstein
  2016-03-16 14:10 ` [PATCH v3 1/3] tmem: add tmem_disable() function Doug Goldstein
  2016-03-16 14:11 ` [PATCH v3 2/3] tmem: drop direct usage of opt_tmem Doug Goldstein
@ 2016-03-16 14:11 ` Doug Goldstein
  2 siblings, 0 replies; 4+ messages in thread
From: Doug Goldstein @ 2016-03-16 14:11 UTC (permalink / raw)
  To: xen-devel; +Cc: Keir Fraser, Doug Goldstein, Jan Beulich, Andrew Cooper

Wrap the various tmem functions with the Kconfig generated CONFIG_TMEM
option allowing users to build Xen without tmem support.

Signed-off-by: Doug Goldstein <cardoe@cardoe.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
---
CC: Keir Fraser <keir@xen.org>
CC: Jan Beulich <jbeulich@suse.com>
CC: Andrew Cooper <andrew.cooper3@citrix.com>
CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

change since v2:
- actually do all the tweaks to the Makefile suggested by Jan
changes from v1:
- add description provided by Konrad (thanks!)
- tweaks to Makefile suggested by Jan
- other fixes suggested by Jan
---
 xen/arch/x86/x86_64/compat/entry.S |  4 ++++
 xen/arch/x86/x86_64/entry.S        |  4 ++++
 xen/common/Kconfig                 | 10 ++++++++++
 xen/common/Makefile                |  8 +++++---
 xen/include/xen/hypercall.h        |  4 ++++
 xen/include/xen/tmem.h             | 26 ++++++++++++++++++++++++++
 xen/include/xen/tmem_xen.h         | 11 +++++++++++
 7 files changed, 64 insertions(+), 3 deletions(-)

diff --git a/xen/arch/x86/x86_64/compat/entry.S b/xen/arch/x86/x86_64/compat/entry.S
index 927439d..5218f8a 100644
--- a/xen/arch/x86/x86_64/compat/entry.S
+++ b/xen/arch/x86/x86_64/compat/entry.S
@@ -345,6 +345,10 @@ compat_crash_page_fault:
 #define compat_kexec_op do_ni_hypercall
 #endif
 
+#ifndef CONFIG_TMEM
+#define do_tmem_op do_ni_hypercall
+#endif
+
 #ifndef CONFIG_XENOPROF
 #define compat_xenoprof_op do_ni_hypercall
 #endif
diff --git a/xen/arch/x86/x86_64/entry.S b/xen/arch/x86/x86_64/entry.S
index dd7f114..cab9763 100644
--- a/xen/arch/x86/x86_64/entry.S
+++ b/xen/arch/x86/x86_64/entry.S
@@ -681,6 +681,10 @@ ENTRY(exception_table)
 #define do_kexec_op do_ni_hypercall
 #endif
 
+#ifndef CONFIG_TMEM
+#define do_tmem_op do_ni_hypercall
+#endif
+
 #ifndef CONFIG_XENOPROF
 #define do_xenoprof_op do_ni_hypercall
 #endif
diff --git a/xen/common/Kconfig b/xen/common/Kconfig
index 8fbc46d..39b0fa7 100644
--- a/xen/common/Kconfig
+++ b/xen/common/Kconfig
@@ -87,6 +87,16 @@ config LATE_HWDOM
 
 	  If unsure, say N.
 
+# Enables transactional memory support
+config TMEM
+	def_bool y
+	prompt "Transactional Memory Support" if EXPERT = "y"
+	---help---
+	  Transcendent memory allows PV-aware guests to collaborate on memory
+	  usage. Guests can 'swap' their memory to the hypervisor or have an
+	  collective pool of memory shared across guests. The end result is
+	  less memory usage by guests allowing higher guest density.
+
 # Adds support for Xenoprof
 config XENOPROF
 	def_bool y
diff --git a/xen/common/Makefile b/xen/common/Makefile
index 82625a5..77de27e 100644
--- a/xen/common/Makefile
+++ b/xen/common/Makefile
@@ -49,8 +49,6 @@ obj-y += sysctl.o
 obj-y += tasklet.o
 obj-y += time.o
 obj-y += timer.o
-obj-y += tmem.o
-obj-y += tmem_xen.o
 obj-y += trace.o
 obj-y += version.o
 obj-y += vm_event.o
@@ -65,7 +63,11 @@ obj-bin-$(CONFIG_X86) += $(foreach n,decompress bunzip2 unxz unlzma unlzo unlz4
 obj-$(perfc)       += perfc.o
 obj-$(crash_debug) += gdbstub.o
 
-obj-$(CONFIG_COMPAT) += $(addprefix compat/,domain.o kernel.o memory.o multicall.o tmem_xen.o xlat.o)
+obj-$(CONFIG_COMPAT) += $(addprefix compat/,domain.o kernel.o memory.o multicall.o xlat.o)
+
+tmem-y := tmem.o tmem_xen.o
+tmem-$(CONFIG_COMPAT) += compat/tmem_xen.o
+obj-$(CONFIG_TMEM) += $(tmem-y)
 
 subdir-$(CONFIG_X86) += hvm
 
diff --git a/xen/include/xen/hypercall.h b/xen/include/xen/hypercall.h
index 26cb615..0c8ae0e 100644
--- a/xen/include/xen/hypercall.h
+++ b/xen/include/xen/hypercall.h
@@ -133,9 +133,13 @@ extern long
 do_xsm_op(
     XEN_GUEST_HANDLE_PARAM(xsm_op_t) u_xsm_op);
 
+#ifdef CONFIG_TMEM
 extern long
 do_tmem_op(
     XEN_GUEST_HANDLE_PARAM(tmem_op_t) uops);
+#else
+#define do_tmem_op do_ni_hypercall
+#endif
 
 extern long
 do_xenoprof_op(int op, XEN_GUEST_HANDLE_PARAM(void) arg);
diff --git a/xen/include/xen/tmem.h b/xen/include/xen/tmem.h
index 32a542a..414a14d 100644
--- a/xen/include/xen/tmem.h
+++ b/xen/include/xen/tmem.h
@@ -11,9 +11,35 @@
 
 struct xen_sysctl_tmem_op;
 
+#ifdef CONFIG_TMEM
 extern int tmem_control(struct xen_sysctl_tmem_op *op);
 extern void tmem_destroy(void *);
 extern void *tmem_relinquish_pages(unsigned int, unsigned int);
 extern unsigned long tmem_freeable_pages(void);
+#else
+static inline int
+tmem_control(struct xen_sysctl_tmem_op *op)
+{
+    return -ENOSYS;
+}
+
+static inline void
+tmem_destroy(void *p)
+{
+    return;
+}
+
+static inline void *
+tmem_relinquish_pages(unsigned int x, unsigned int y)
+{
+    return NULL;
+}
+
+static inline unsigned long
+tmem_freeable_pages(void)
+{
+    return 0;
+}
+#endif /* CONFIG_TMEM */
 
 #endif /* __XEN_TMEM_H__ */
diff --git a/xen/include/xen/tmem_xen.h b/xen/include/xen/tmem_xen.h
index f516bbe..19ed835 100644
--- a/xen/include/xen/tmem_xen.h
+++ b/xen/include/xen/tmem_xen.h
@@ -63,6 +63,7 @@ static inline bool_t tmem_shared_auth(void)
     return opt_tmem_shared_auth;
 }
 
+#ifdef CONFIG_TMEM
 extern bool_t opt_tmem;
 static inline bool_t tmem_enabled(void)
 {
@@ -73,6 +74,16 @@ static inline void tmem_disable(void)
 {
     opt_tmem = 0;
 }
+#else
+static inline bool_t tmem_enabled(void)
+{
+    return 0;
+}
+
+static inline void tmem_disable(void)
+{
+}
+#endif /* CONFIG_TMEM */
 
 /*
  * Memory free page list management
-- 
2.4.10


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^ permalink raw reply related	[flat|nested] 4+ messages in thread
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Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-03-16 14:10 [PATCH v3 0/3] Allow tmem to be disabled via Kconfig Doug Goldstein
2016-03-16 14:10 ` [PATCH v3 1/3] tmem: add tmem_disable() function Doug Goldstein
2016-03-16 14:11 ` [PATCH v3 2/3] tmem: drop direct usage of opt_tmem Doug Goldstein
2016-03-16 14:11 ` [PATCH v3 3/3] tmem: allow tmem to be disabled with Kconfig Doug Goldstein

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