Skip to content

K
Kernel

openeuler / Kernel
1 年多 前同步成功

通知 8
Star 0
Fork 0
K
Kernel
切换分支/标签
  1. 26 3月, 2018 9 次提交
  3. 12 3月, 2018 1 次提交
  5. 16 11月, 2017 1 次提交
    • M
      mm: remove __GFP_COLD · 453f85d4
      由 Mel Gorman 提交于 
      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.netSigned-off-by: NMel Gorman <mgorman@techsingularity.net>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      453f85d4
  7. 24 10月, 2017 1 次提交
  9. 16 8月, 2017 4 次提交
  11. 15 8月, 2017 8 次提交
  13. 19 6月, 2017 1 次提交
  15. 16 6月, 2017 1 次提交
    • J
      networking: introduce and use skb_put_data() · 59ae1d12
      由 Johannes Berg 提交于 
      A common pattern with skb_put() is to just want to memcpy()
some data into the new space, introduce skb_put_data() for
this.

An spatch similar to the one for skb_put_zero() converts many
of the places using it:

    @@
    identifier p, p2;
    expression len, skb, data;
    type t, t2;
    @@
    (
    -p = skb_put(skb, len);
    +p = skb_put_data(skb, data, len);
    |
    -p = (t)skb_put(skb, len);
    +p = skb_put_data(skb, data, len);
    )
    (
    p2 = (t2)p;
    -memcpy(p2, data, len);
    |
    -memcpy(p, data, len);
    )

    @@
    type t, t2;
    identifier p, p2;
    expression skb, data;
    @@
    t *p;
    ...
    (
    -p = skb_put(skb, sizeof(t));
    +p = skb_put_data(skb, data, sizeof(t));
    |
    -p = (t *)skb_put(skb, sizeof(t));
    +p = skb_put_data(skb, data, sizeof(t));
    )
    (
    p2 = (t2)p;
    -memcpy(p2, data, sizeof(*p));
    |
    -memcpy(p, data, sizeof(*p));
    )

    @@
    expression skb, len, data;
    @@
    -memcpy(skb_put(skb, len), data, len);
    +skb_put_data(skb, data, len);

(again, manually post-processed to retain some comments)
Reviewed-by: NStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      59ae1d12
  17. 07 4月, 2017 1 次提交
    • F
      liquidio: fix Octeon core watchdog timeout false alarm · bb54be58
      由 Felix Manlunas 提交于 
      Detection of watchdog timeout of Octeon cores is flawed and susceptible to
false alarms.  Refactor by removing the detection code, and in its place,
leverage existing code that monitors for an indication from the NIC
firmware that an Octeon core crashed; expand the meaning of the indication
to "an Octeon core crashed or its watchdog timer expired".  Detection of
watchdog timeout is now delegated to an exception handler in the NIC
firmware; this is free of false alarms.

Also if there's an Octeon core crash or watchdog timeout:
(1) Disable VF Ethernet links.
(2) Decrement the module refcount by an amount equal to the number of
    active VFs of the NIC whose Octeon core crashed or had a watchdog
    timeout.  The refcount will continue to reflect the active VFs of
    other liquidio NIC(s) (if present) whose Octeon cores are faultless.

Item (2) is needed to avoid the case of not being able to unload the driver
because the module refcount is stuck at some non-zero number.  There is
code that, in normal cases, decrements the refcount upon receiving a
message from the firmware that a VF driver was unloaded.  But in
exceptional cases like an Octeon core crash or watchdog timeout, arrival of
that particular message from the firmware might be unreliable.  That normal
case code is changed to not touch the refcount in the exceptional case to
avoid contention (over the refcount) with the liquidio_watchdog kernel
thread who will carry out item (2).
Signed-off-by: NFelix Manlunas <felix.manlunas@cavium.com>
Signed-off-by: NDerek Chickles <derek.chickles@cavium.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      bb54be58
  19. 23 3月, 2017 1 次提交
  21. 22 3月, 2017 1 次提交
  23. 10 3月, 2017 1 次提交
    • V
      liquidio: improve UDP TX performance · 67e303e0
      由 VSR Burru 提交于 
      Improve UDP TX performance by:
* reducing the ring size from 2K to 512
* replacing the numerous streaming DMA allocations for info buffers and
  gather lists with one large consistent DMA allocation per ring

BQL is not effective here.  We reduced the ring size because there is heavy
overhead with dma_map_single every so often.  With iommu=on, dma_map_single
in PF Tx data path was taking longer time (~700usec) for every ~250
packets.  Debugged intel_iommu code, and found that PF driver is utilizing
too many static IO virtual address mapping entries (for gather list entries
and info buffers): about 100K entries for two PF's each using 8 rings.
Also, finding an empty entry (in rbtree of device domain's iova mapping in
kernel) during Tx path becomes a bottleneck every so often; the loop to
find the empty entry goes through over 40K iterations; this is too costly
and was the major overhead.  Overhead is low when this loop quits quickly.

Netperf benchmark numbers before and after patch:

PF UDP TX
+--------+--------+------------+------------+---------+
|        |        |  Before    |  After     |         |
| Number |        |  Patch     |  Patch     |         |
|  of    | Packet | Throughput | Throughput | Percent |
| Flows  |  Size  |  (Gbps)    |  (Gbps)    | Change  |
+--------+--------+------------+------------+---------+
|        |   360  |   0.52     |   0.93     |  +78.9  |
|   1    |  1024  |   1.62     |   2.84     |  +75.3  |
|        |  1518  |   2.44     |   4.21     |  +72.5  |
+--------+--------+------------+------------+---------+
|        |   360  |   0.45     |   1.59     | +253.3  |
|   4    |  1024  |   1.34     |   5.48     | +308.9  |
|        |  1518  |   2.27     |   8.31     | +266.1  |
+--------+--------+------------+------------+---------+
|        |   360  |   0.40     |   1.61     | +302.5  |
|   8    |  1024  |   1.64     |   4.24     | +158.5  |
|        |  1518  |   2.87     |   6.52     | +127.2  |
+--------+--------+------------+------------+---------+

VF UDP TX
+--------+--------+------------+------------+---------+
|        |        |  Before    |  After     |         |
| Number |        |  Patch     |  Patch     |         |
|  of    | Packet | Throughput | Throughput | Percent |
| Flows  |  Size  |  (Gbps)    |  (Gbps)    | Change  |
+--------+--------+------------+------------+---------+
|        |   360  |   1.28     |   1.49     |  +16.4  |
|   1    |  1024  |   4.44     |   4.39     |   -1.1  |
|        |  1518  |   6.08     |   6.51     |   +7.1  |
+--------+--------+------------+------------+---------+
|        |   360  |   2.35     |   2.35     |    0.0  |
|   4    |  1024  |   6.41     |   8.07     |  +25.9  |
|        |  1518  |   9.56     |   9.54     |   -0.2  |
+--------+--------+------------+------------+---------+
|        |   360  |   3.41     |   3.65     |   +7.0  |
|   8    |  1024  |   9.35     |   9.34     |   -0.1  |
|        |  1518  |   9.56     |   9.57     |   +0.1  |
+--------+--------+------------+------------+---------+
Signed-off-by: NVSR Burru <veerasenareddy.burru@cavium.com>
Signed-off-by: NFelix Manlunas <felix.manlunas@cavium.com>
Signed-off-by: NDerek Chickles <derek.chickles@cavium.com>
Signed-off-by: NRaghu Vatsavayi <raghu.vatsavayi@cavium.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      67e303e0
  25. 09 12月, 2016 1 次提交
  27. 16 11月, 2016 2 次提交
  29. 18 10月, 2016 1 次提交
  31. 03 9月, 2016 2 次提交
  33. 01 9月, 2016 1 次提交
  35. 05 7月, 2016 3 次提交