<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git/drivers/net/ethernet/amazon, branch v4.17.1</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v4.17.1</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=v4.17.1'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2018-03-26T16:47:56+00:00</updated>
<entry>
<title>net: ena: Eliminate duplicate barriers on weakly-ordered archs</title>
<updated>2018-03-26T16:47:56+00:00</updated>
<author>
<name>Sinan Kaya</name>
<email>okaya@codeaurora.org</email>
</author>
<published>2018-03-25T14:39:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=6d2e1a8d5e25e5f4563f5ea24bcb5da1ae261b26'/>
<id>urn:sha1:6d2e1a8d5e25e5f4563f5ea24bcb5da1ae261b26</id>
<content type='text'>
Code includes barrier() followed by writel(). writel() already has a
barrier on some architectures like arm64.

This ends up CPU observing two barriers back to back before executing the
register write.

Create a new wrapper function with relaxed write operator. Use the new
wrapper when a write is following a barrier().

Since code already has an explicit barrier call, changing writel() to
writel_relaxed() and adding mmiowb() for ordering protection.

Signed-off-by: Sinan Kaya &lt;okaya@codeaurora.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net</title>
<updated>2018-01-09T15:37:00+00:00</updated>
<author>
<name>David S. Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2018-01-09T15:37:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=a0ce093180f2bbb832b3f5583adc640ad67ea568'/>
<id>urn:sha1:a0ce093180f2bbb832b3f5583adc640ad67ea568</id>
<content type='text'>
</content>
</entry>
<entry>
<title>net: ena: fix error handling in ena_down() sequence</title>
<updated>2018-01-03T17:21:00+00:00</updated>
<author>
<name>Netanel Belgazal</name>
<email>netanel@amazon.com</email>
</author>
<published>2018-01-03T06:17:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=ee4552aaf3fef5345199b8a82e40be7245b289fb'/>
<id>urn:sha1:ee4552aaf3fef5345199b8a82e40be7245b289fb</id>
<content type='text'>
ENA admin command queue errors are not handled as part of ena_down().
As a result, in case of error admin queue transitions to non-running
state and aborts all subsequent commands including those coming from
ena_up(). Reset scheduled by the driver from the timer service
context would not proceed due to sharing rtnl with ena_up()/ena_down()

Signed-off-by: Netanel Belgazal &lt;netanel@amazon.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>net: ena: unmask MSI-X only after device initialization is completed</title>
<updated>2018-01-03T17:21:00+00:00</updated>
<author>
<name>Netanel Belgazal</name>
<email>netanel@amazon.com</email>
</author>
<published>2018-01-03T06:17:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=7853b49ce8e0ef6364d24512b287463841d71bd3'/>
<id>urn:sha1:7853b49ce8e0ef6364d24512b287463841d71bd3</id>
<content type='text'>
Under certain conditions MSI-X interrupt might arrive right after it
was unmasked in ena_up(). There is a chance it would be processed by
the driver before device ENA_FLAG_DEV_UP flag is set. In such a case
the interrupt is ignored.
ENA device operates in auto-masked mode, therefore ignoring
interrupt leaves it masked for good.
Moving unmask of interrupt to be the last step in ena_up().

Signed-off-by: Netanel Belgazal &lt;netanel@amazon.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>net: ena: increase ena driver version to 1.5.0</title>
<updated>2018-01-02T19:35:12+00:00</updated>
<author>
<name>Netanel Belgazal</name>
<email>netanel@amazon.com</email>
</author>
<published>2017-12-28T21:31:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=70097445686209f2b365b51f8154be0ee5b0ba53'/>
<id>urn:sha1:70097445686209f2b365b51f8154be0ee5b0ba53</id>
<content type='text'>
Signed-off-by: Netanel Belgazal &lt;netanel@amazon.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>net: ena: add detection and recovery mechanism for handling missed/misrouted MSI-X</title>
<updated>2018-01-02T19:35:12+00:00</updated>
<author>
<name>Netanel Belgazal</name>
<email>netanel@amazon.com</email>
</author>
<published>2017-12-28T21:31:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=8510e1a3d16c7e4e2b47c9675b18725407c616b7'/>
<id>urn:sha1:8510e1a3d16c7e4e2b47c9675b18725407c616b7</id>
<content type='text'>
A mechanism for detection of stuck Rx/Tx rings due to missed or
misrouted interrupts.
Check if there are unhandled completion descriptors before the first
MSI-X interrupt arrived.
The check is per queue and per interrupt vector.
Once such condition is detected, driver and device reset is scheduled.

Signed-off-by: Netanel Belgazal &lt;netanel@amazon.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>treewide: setup_timer() -&gt; timer_setup()</title>
<updated>2017-11-21T23:57:07+00:00</updated>
<author>
<name>Kees Cook</name>
<email>keescook@chromium.org</email>
</author>
<published>2017-10-16T21:43:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=e99e88a9d2b067465adaa9c111ada99a041bef9a'/>
<id>urn:sha1:e99e88a9d2b067465adaa9c111ada99a041bef9a</id>
<content type='text'>
This converts all remaining cases of the old setup_timer() API into using
timer_setup(), where the callback argument is the structure already
holding the struct timer_list. These should have no behavioral changes,
since they just change which pointer is passed into the callback with
the same available pointers after conversion. It handles the following
examples, in addition to some other variations.

Casting from unsigned long:

    void my_callback(unsigned long data)
    {
        struct something *ptr = (struct something *)data;
    ...
    }
    ...
    setup_timer(&amp;ptr-&gt;my_timer, my_callback, ptr);

and forced object casts:

    void my_callback(struct something *ptr)
    {
    ...
    }
    ...
    setup_timer(&amp;ptr-&gt;my_timer, my_callback, (unsigned long)ptr);

become:

    void my_callback(struct timer_list *t)
    {
        struct something *ptr = from_timer(ptr, t, my_timer);
    ...
    }
    ...
    timer_setup(&amp;ptr-&gt;my_timer, my_callback, 0);

Direct function assignments:

    void my_callback(unsigned long data)
    {
        struct something *ptr = (struct something *)data;
    ...
    }
    ...
    ptr-&gt;my_timer.function = my_callback;

have a temporary cast added, along with converting the args:

    void my_callback(struct timer_list *t)
    {
        struct something *ptr = from_timer(ptr, t, my_timer);
    ...
    }
    ...
    ptr-&gt;my_timer.function = (TIMER_FUNC_TYPE)my_callback;

And finally, callbacks without a data assignment:

    void my_callback(unsigned long data)
    {
    ...
    }
    ...
    setup_timer(&amp;ptr-&gt;my_timer, my_callback, 0);

have their argument renamed to verify they're unused during conversion:

    void my_callback(struct timer_list *unused)
    {
    ...
    }
    ...
    timer_setup(&amp;ptr-&gt;my_timer, my_callback, 0);

The conversion is done with the following Coccinelle script:

spatch --very-quiet --all-includes --include-headers \
	-I ./arch/x86/include -I ./arch/x86/include/generated \
	-I ./include -I ./arch/x86/include/uapi \
	-I ./arch/x86/include/generated/uapi -I ./include/uapi \
	-I ./include/generated/uapi --include ./include/linux/kconfig.h \
	--dir . \
	--cocci-file ~/src/data/timer_setup.cocci

@fix_address_of@
expression e;
@@

 setup_timer(
-&amp;(e)
+&amp;e
 , ...)

// Update any raw setup_timer() usages that have a NULL callback, but
// would otherwise match change_timer_function_usage, since the latter
// will update all function assignments done in the face of a NULL
// function initialization in setup_timer().
@change_timer_function_usage_NULL@
expression _E;
identifier _timer;
type _cast_data;
@@

(
-setup_timer(&amp;_E-&gt;_timer, NULL, _E);
+timer_setup(&amp;_E-&gt;_timer, NULL, 0);
|
-setup_timer(&amp;_E-&gt;_timer, NULL, (_cast_data)_E);
+timer_setup(&amp;_E-&gt;_timer, NULL, 0);
|
-setup_timer(&amp;_E._timer, NULL, &amp;_E);
+timer_setup(&amp;_E._timer, NULL, 0);
|
-setup_timer(&amp;_E._timer, NULL, (_cast_data)&amp;_E);
+timer_setup(&amp;_E._timer, NULL, 0);
)

@change_timer_function_usage@
expression _E;
identifier _timer;
struct timer_list _stl;
identifier _callback;
type _cast_func, _cast_data;
@@

(
-setup_timer(&amp;_E-&gt;_timer, _callback, _E);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E-&gt;_timer, &amp;_callback, _E);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E-&gt;_timer, _callback, (_cast_data)_E);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E-&gt;_timer, &amp;_callback, (_cast_data)_E);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E-&gt;_timer, (_cast_func)_callback, _E);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E-&gt;_timer, (_cast_func)&amp;_callback, _E);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E-&gt;_timer, (_cast_func)_callback, (_cast_data)_E);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E-&gt;_timer, (_cast_func)&amp;_callback, (_cast_data)_E);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, _callback, (_cast_data)_E);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, _callback, (_cast_data)&amp;_E);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, &amp;_callback, (_cast_data)_E);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, &amp;_callback, (_cast_data)&amp;_E);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, (_cast_func)_callback, (_cast_data)_E);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, (_cast_func)_callback, (_cast_data)&amp;_E);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, (_cast_func)&amp;_callback, (_cast_data)_E);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, (_cast_func)&amp;_callback, (_cast_data)&amp;_E);
+timer_setup(&amp;_E._timer, _callback, 0);
|
 _E-&gt;_timer@_stl.function = _callback;
|
 _E-&gt;_timer@_stl.function = &amp;_callback;
|
 _E-&gt;_timer@_stl.function = (_cast_func)_callback;
|
 _E-&gt;_timer@_stl.function = (_cast_func)&amp;_callback;
|
 _E._timer@_stl.function = _callback;
|
 _E._timer@_stl.function = &amp;_callback;
|
 _E._timer@_stl.function = (_cast_func)_callback;
|
 _E._timer@_stl.function = (_cast_func)&amp;_callback;
)

// callback(unsigned long arg)
@change_callback_handle_cast
 depends on change_timer_function_usage@
identifier change_timer_function_usage._callback;
identifier change_timer_function_usage._timer;
type _origtype;
identifier _origarg;
type _handletype;
identifier _handle;
@@

 void _callback(
-_origtype _origarg
+struct timer_list *t
 )
 {
(
	... when != _origarg
	_handletype *_handle =
-(_handletype *)_origarg;
+from_timer(_handle, t, _timer);
	... when != _origarg
|
	... when != _origarg
	_handletype *_handle =
-(void *)_origarg;
+from_timer(_handle, t, _timer);
	... when != _origarg
|
	... when != _origarg
	_handletype *_handle;
	... when != _handle
	_handle =
-(_handletype *)_origarg;
+from_timer(_handle, t, _timer);
	... when != _origarg
|
	... when != _origarg
	_handletype *_handle;
	... when != _handle
	_handle =
-(void *)_origarg;
+from_timer(_handle, t, _timer);
	... when != _origarg
)
 }

// callback(unsigned long arg) without existing variable
@change_callback_handle_cast_no_arg
 depends on change_timer_function_usage &amp;&amp;
                     !change_callback_handle_cast@
identifier change_timer_function_usage._callback;
identifier change_timer_function_usage._timer;
type _origtype;
identifier _origarg;
type _handletype;
@@

 void _callback(
-_origtype _origarg
+struct timer_list *t
 )
 {
+	_handletype *_origarg = from_timer(_origarg, t, _timer);
+
	... when != _origarg
-	(_handletype *)_origarg
+	_origarg
	... when != _origarg
 }

// Avoid already converted callbacks.
@match_callback_converted
 depends on change_timer_function_usage &amp;&amp;
            !change_callback_handle_cast &amp;&amp;
	    !change_callback_handle_cast_no_arg@
identifier change_timer_function_usage._callback;
identifier t;
@@

 void _callback(struct timer_list *t)
 { ... }

// callback(struct something *handle)
@change_callback_handle_arg
 depends on change_timer_function_usage &amp;&amp;
	    !match_callback_converted &amp;&amp;
            !change_callback_handle_cast &amp;&amp;
            !change_callback_handle_cast_no_arg@
identifier change_timer_function_usage._callback;
identifier change_timer_function_usage._timer;
type _handletype;
identifier _handle;
@@

 void _callback(
-_handletype *_handle
+struct timer_list *t
 )
 {
+	_handletype *_handle = from_timer(_handle, t, _timer);
	...
 }

// If change_callback_handle_arg ran on an empty function, remove
// the added handler.
@unchange_callback_handle_arg
 depends on change_timer_function_usage &amp;&amp;
	    change_callback_handle_arg@
identifier change_timer_function_usage._callback;
identifier change_timer_function_usage._timer;
type _handletype;
identifier _handle;
identifier t;
@@

 void _callback(struct timer_list *t)
 {
-	_handletype *_handle = from_timer(_handle, t, _timer);
 }

// We only want to refactor the setup_timer() data argument if we've found
// the matching callback. This undoes changes in change_timer_function_usage.
@unchange_timer_function_usage
 depends on change_timer_function_usage &amp;&amp;
            !change_callback_handle_cast &amp;&amp;
            !change_callback_handle_cast_no_arg &amp;&amp;
	    !change_callback_handle_arg@
expression change_timer_function_usage._E;
identifier change_timer_function_usage._timer;
identifier change_timer_function_usage._callback;
type change_timer_function_usage._cast_data;
@@

(
-timer_setup(&amp;_E-&gt;_timer, _callback, 0);
+setup_timer(&amp;_E-&gt;_timer, _callback, (_cast_data)_E);
|
-timer_setup(&amp;_E._timer, _callback, 0);
+setup_timer(&amp;_E._timer, _callback, (_cast_data)&amp;_E);
)

// If we fixed a callback from a .function assignment, fix the
// assignment cast now.
@change_timer_function_assignment
 depends on change_timer_function_usage &amp;&amp;
            (change_callback_handle_cast ||
             change_callback_handle_cast_no_arg ||
             change_callback_handle_arg)@
expression change_timer_function_usage._E;
identifier change_timer_function_usage._timer;
identifier change_timer_function_usage._callback;
type _cast_func;
typedef TIMER_FUNC_TYPE;
@@

(
 _E-&gt;_timer.function =
-_callback
+(TIMER_FUNC_TYPE)_callback
 ;
|
 _E-&gt;_timer.function =
-&amp;_callback
+(TIMER_FUNC_TYPE)_callback
 ;
|
 _E-&gt;_timer.function =
-(_cast_func)_callback;
+(TIMER_FUNC_TYPE)_callback
 ;
|
 _E-&gt;_timer.function =
-(_cast_func)&amp;_callback
+(TIMER_FUNC_TYPE)_callback
 ;
|
 _E._timer.function =
-_callback
+(TIMER_FUNC_TYPE)_callback
 ;
|
 _E._timer.function =
-&amp;_callback;
+(TIMER_FUNC_TYPE)_callback
 ;
|
 _E._timer.function =
-(_cast_func)_callback
+(TIMER_FUNC_TYPE)_callback
 ;
|
 _E._timer.function =
-(_cast_func)&amp;_callback
+(TIMER_FUNC_TYPE)_callback
 ;
)

// Sometimes timer functions are called directly. Replace matched args.
@change_timer_function_calls
 depends on change_timer_function_usage &amp;&amp;
            (change_callback_handle_cast ||
             change_callback_handle_cast_no_arg ||
             change_callback_handle_arg)@
expression _E;
identifier change_timer_function_usage._timer;
identifier change_timer_function_usage._callback;
type _cast_data;
@@

 _callback(
(
-(_cast_data)_E
+&amp;_E-&gt;_timer
|
-(_cast_data)&amp;_E
+&amp;_E._timer
|
-_E
+&amp;_E-&gt;_timer
)
 )

// If a timer has been configured without a data argument, it can be
// converted without regard to the callback argument, since it is unused.
@match_timer_function_unused_data@
expression _E;
identifier _timer;
identifier _callback;
@@

(
-setup_timer(&amp;_E-&gt;_timer, _callback, 0);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E-&gt;_timer, _callback, 0L);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E-&gt;_timer, _callback, 0UL);
+timer_setup(&amp;_E-&gt;_timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, _callback, 0);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, _callback, 0L);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_E._timer, _callback, 0UL);
+timer_setup(&amp;_E._timer, _callback, 0);
|
-setup_timer(&amp;_timer, _callback, 0);
+timer_setup(&amp;_timer, _callback, 0);
|
-setup_timer(&amp;_timer, _callback, 0L);
+timer_setup(&amp;_timer, _callback, 0);
|
-setup_timer(&amp;_timer, _callback, 0UL);
+timer_setup(&amp;_timer, _callback, 0);
|
-setup_timer(_timer, _callback, 0);
+timer_setup(_timer, _callback, 0);
|
-setup_timer(_timer, _callback, 0L);
+timer_setup(_timer, _callback, 0);
|
-setup_timer(_timer, _callback, 0UL);
+timer_setup(_timer, _callback, 0);
)

@change_callback_unused_data
 depends on match_timer_function_unused_data@
identifier match_timer_function_unused_data._callback;
type _origtype;
identifier _origarg;
@@

 void _callback(
-_origtype _origarg
+struct timer_list *unused
 )
 {
	... when != _origarg
 }

Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
</content>
</entry>
<entry>
<title>net: ena: fix race condition between device reset and link up setup</title>
<updated>2017-11-20T02:35:16+00:00</updated>
<author>
<name>Netanel Belgazal</name>
<email>netanel@amazon.com</email>
</author>
<published>2017-11-19T18:03:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=d18e4f6834451dbc12407c26acd5fae4da14c489'/>
<id>urn:sha1:d18e4f6834451dbc12407c26acd5fae4da14c489</id>
<content type='text'>
In rare cases, ena driver would reset and re-start the device,
for example, in case of misbehaving application that causes
transmit timeout

The first step in the reset procedure is to stop the Tx traffic by
calling ena_carrier_off().

After the driver have just started the device reset procedure, device
happens to send an asynchronous notification (via AENQ) to the driver
than there was a link change (to link-up state).
This link change is mapped to a call to netif_carrier_on() which
re-activates the Tx queues, violating the assumption of no tx traffic
until device reset is completed, as the reset task might still be in
the process of queues initialization, leading to an access to
uninitialized memory.

Signed-off-by: Netanel Belgazal &lt;netanel@amazon.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>Merge branch 'akpm' (patches from Andrew)</title>
<updated>2017-11-16T03:42:40+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2017-11-16T03:42:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=7c225c69f86c934e3be9be63ecde754e286838d7'/>
<id>urn:sha1:7c225c69f86c934e3be9be63ecde754e286838d7</id>
<content type='text'>
Merge updates from Andrew Morton:

 - a few misc bits

 - ocfs2 updates

 - almost all of MM

* emailed patches from Andrew Morton &lt;akpm@linux-foundation.org&gt;: (131 commits)
  memory hotplug: fix comments when adding section
  mm: make alloc_node_mem_map a void call if we don't have CONFIG_FLAT_NODE_MEM_MAP
  mm: simplify nodemask printing
  mm,oom_reaper: remove pointless kthread_run() error check
  mm/page_ext.c: check if page_ext is not prepared
  writeback: remove unused function parameter
  mm: do not rely on preempt_count in print_vma_addr
  mm, sparse: do not swamp log with huge vmemmap allocation failures
  mm/hmm: remove redundant variable align_end
  mm/list_lru.c: mark expected switch fall-through
  mm/shmem.c: mark expected switch fall-through
  mm/page_alloc.c: broken deferred calculation
  mm: don't warn about allocations which stall for too long
  fs: fuse: account fuse_inode slab memory as reclaimable
  mm, page_alloc: fix potential false positive in __zone_watermark_ok
  mm: mlock: remove lru_add_drain_all()
  mm, sysctl: make NUMA stats configurable
  shmem: convert shmem_init_inodecache() to void
  Unify migrate_pages and move_pages access checks
  mm, pagevec: rename pagevec drained field
  ...
</content>
</entry>
<entry>
<title>mm: remove __GFP_COLD</title>
<updated>2017-11-16T02:21:06+00:00</updated>
<author>
<name>Mel Gorman</name>
<email>mgorman@techsingularity.net</email>
</author>
<published>2017-11-16T01:38:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=453f85d43fa9ee243f0fc3ac4e1be45615301e3f'/>
<id>urn:sha1:453f85d43fa9ee243f0fc3ac4e1be45615301e3f</id>
<content type='text'>
As the page free path makes no distinction between cache hot and cold
pages, there is no real useful ordering of pages in the free list that
allocation requests can take advantage of.  Juding from the users of
__GFP_COLD, it is likely that a number of them are the result of copying
other sites instead of actually measuring the impact.  Remove the
__GFP_COLD parameter which simplifies a number of paths in the page
allocator.

This is potentially controversial but bear in mind that the size of the
per-cpu pagelists versus modern cache sizes means that the whole per-cpu
list can often fit in the L3 cache.  Hence, there is only a potential
benefit for microbenchmarks that alloc/free pages in a tight loop.  It's
even worse when THP is taken into account which has little or no chance
of getting a cache-hot page as the per-cpu list is bypassed and the
zeroing of multiple pages will thrash the cache anyway.

The truncate microbenchmarks are not shown as this patch affects the
allocation path and not the free path.  A page fault microbenchmark was
tested but it showed no sigificant difference which is not surprising
given that the __GFP_COLD branches are a miniscule percentage of the
fault path.

Link: http://lkml.kernel.org/r/20171018075952.10627-9-mgorman@techsingularity.net
Signed-off-by: Mel Gorman &lt;mgorman@techsingularity.net&gt;
Acked-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Dave Chinner &lt;david@fromorbit.com&gt;
Cc: Dave Hansen &lt;dave.hansen@intel.com&gt;
Cc: Jan Kara &lt;jack@suse.cz&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
</feed>
