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  1. 21 7月, 2017 1 次提交
  3. 16 7月, 2017 1 次提交
  5. 04 7月, 2017 1 次提交
  7. 05 6月, 2017 1 次提交
    • A
      x86/mm: Pass flush_tlb_info to flush_tlb_others() etc · a2055abe
      由 Andy Lutomirski 提交于 
      Rather than passing all the contents of flush_tlb_info to
flush_tlb_others(), pass a pointer to the structure directly. For
consistency, this also removes the unnecessary cpu parameter from
uv_flush_tlb_others() to make its signature match the other
*flush_tlb_others() functions.

This serves two purposes:

 - It will dramatically simplify future patches that change struct
   flush_tlb_info, which I'm planning to do.

 - struct flush_tlb_info is an adequate description of what to do
   for a local flush, too, so by reusing it we can remove duplicated
   code between local and remove flushes in a future patch.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Acked-by: NRik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Nadav Amit <namit@vmware.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
[ Fix build warning. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>
      a2055abe
  9. 15 5月, 2017 1 次提交
    • P
      x86/tsc: Remodel cyc2ns to use seqcount_latch() · 59eaef78
      由 Peter Zijlstra 提交于 
      Replace the custom multi-value scheme with the more regular
seqcount_latch() scheme. Along with scrapping a lot of lines, the latch
scheme is better documented and used in more places.

The immediate benefit however is not being limited on the update side.
The current code has a limit where the writers block which is hit by
future changes.
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>
      59eaef78
  11. 13 3月, 2017 6 次提交
  13. 01 3月, 2017 1 次提交
  15. 10 12月, 2016 1 次提交
  17. 22 9月, 2016 10 次提交
  19. 14 9月, 2016 1 次提交
    • M
      x86: Clean up various simple wrapper functions · f148b41e
      由 Masahiro Yamada 提交于 
      Remove unneeded variables and assignments.

While we are here, let's fix the following as well:

  - Remove unnecessary parentheses
  - Remove unnecessary unsigned-suffix 'U' from constant values
  - Reword the comment in set_apic_id() (suggested by Thomas Gleixner)
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Cc: Alex Thorlton <athorlton@sgi.com>
Cc: Andrew Banman <abanman@sgi.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Daniel J Blueman <daniel@numascale.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Mike Travis <travis@sgi.com>
Cc: Nathan Zimmer <nzimmer@sgi.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steffen Persvold <sp@numascale.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Wei Jiangang <weijg.fnst@cn.fujitsu.com>
Link: http://lkml.kernel.org/r/1473573502-27954-1-git-send-email-yamada.masahiro@socionext.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      f148b41e
  21. 04 5月, 2016 1 次提交
  23. 01 4月, 2016 1 次提交
    • A
      x86/platform/uv: Disable UV BAU by default · 1c532e00
      由 Alex Thorlton 提交于 
      For several years, the common practice has been to boot UVs with the
"nobau" parameter on the command line, to disable the BAU.  We've
decided that it makes more sense to just disable the BAU by default in
the kernel, and provide the option to turn it on, if desired.

For now, having the on/off switch doesn't buy us any more than just
reversing the logic would, but we're working towards having the BAU
enabled by default on UV4.  When those changes are in place, having the
on/off switch will make more sense than an enable flag, since the
default behavior will be different depending on the system version.

I've also added a bit of documentation for the new parameter to
Documentation/kernel-parameters.txt.
Signed-off-by: NAlex Thorlton <athorlton@sgi.com>
Reviewed-by: NHedi Berriche <hedi@sgi.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1459451909-121845-1-git-send-email-athorlton@sgi.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      1c532e00
  25. 05 3月, 2015 1 次提交
  27. 02 3月, 2015 1 次提交
  29. 08 12月, 2014 1 次提交
  31. 03 11月, 2014 1 次提交
  33. 09 8月, 2014 1 次提交
  35. 05 6月, 2014 1 次提交
    • C
      x86/uv: Update the UV3 TLB shootdown logic · a26fd719
      由 Cliff Wickman 提交于 
      Update of TLB shootdown code for UV3.

Kernel function native_flush_tlb_others() calls
uv_flush_tlb_others() on UV to invalidate tlb page definitions
on remote cpus. The UV systems have a hardware 'broadcast assist
unit' which can be used to broadcast shootdown messages to all
cpu's of selected nodes.

The behavior of the BAU has changed only slightly with UV3:

  - UV3 is recognized with is_uv3_hub().
  - UV2 functions and structures (uv2_xxx) are in most cases
    simply renamed to uv2_3_xxx.
  - Some UV2 error workarounds are not needed for UV3.
    (see uv_bau_message_interrupt and enable_timeouts)
Signed-off-by: NCliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/E1WkgWh-0001yJ-3K@eag09.americas.sgi.com
[ Removed a few linebreak uglies. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>
      a26fd719
  37. 13 1月, 2014 1 次提交
    • P
      sched/clock, x86: Rewrite cyc2ns() to avoid the need to disable IRQs · 20d1c86a
      由 Peter Zijlstra 提交于 
      Use a ring-buffer like multi-version object structure which allows
always having a coherent object; we use this to avoid having to
disable IRQs while reading sched_clock() and avoids a problem when
getting an NMI while changing the cyc2ns data.

                        MAINLINE   PRE        POST

    sched_clock_stable: 1          1          1
    (cold) sched_clock: 329841     331312     257223
    (cold) local_clock: 301773     310296     309889
    (warm) sched_clock: 38375      38247      25280
    (warm) local_clock: 100371     102713     85268
    (warm) rdtsc:       27340      27289      24247
    sched_clock_stable: 0          0          0
    (cold) sched_clock: 382634     372706     301224
    (cold) local_clock: 396890     399275     399870
    (warm) sched_clock: 38194      38124      25630
    (warm) local_clock: 143452     148698     129629
    (warm) rdtsc:       27345      27365      24307
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-s567in1e5ekq2nlyhn8f987r@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      20d1c86a
  39. 10 12月, 2013 1 次提交
  41. 24 1月, 2013 1 次提交
  43. 21 12月, 2012 1 次提交
  45. 28 6月, 2012 1 次提交
    • A
      x86/flush_tlb: try flush_tlb_single one by one in flush_tlb_range · e7b52ffd
      由 Alex Shi 提交于 
      x86 has no flush_tlb_range support in instruction level. Currently the
flush_tlb_range just implemented by flushing all page table. That is not
the best solution for all scenarios. In fact, if we just use 'invlpg' to
flush few lines from TLB, we can get the performance gain from later
remain TLB lines accessing.

But the 'invlpg' instruction costs much of time. Its execution time can
compete with cr3 rewriting, and even a bit more on SNB CPU.

So, on a 512 4KB TLB entries CPU, the balance points is at:
	(512 - X) * 100ns(assumed TLB refill cost) =
		X(TLB flush entries) * 100ns(assumed invlpg cost)

Here, X is 256, that is 1/2 of 512 entries.

But with the mysterious CPU pre-fetcher and page miss handler Unit, the
assumed TLB refill cost is far lower then 100ns in sequential access. And
2 HT siblings in one core makes the memory access more faster if they are
accessing the same memory. So, in the patch, I just do the change when
the target entries is less than 1/16 of whole active tlb entries.
Actually, I have no data support for the percentage '1/16', so any
suggestions are welcomed.

As to hugetlb, guess due to smaller page table, and smaller active TLB
entries, I didn't see benefit via my benchmark, so no optimizing now.

My micro benchmark show in ideal scenarios, the performance improves 70
percent in reading. And in worst scenario, the reading/writing
performance is similar with unpatched 3.4-rc4 kernel.

Here is the reading data on my 2P * 4cores *HT NHM EP machine, with THP
'always':

multi thread testing, '-t' paramter is thread number:
	       	        with patch   unpatched 3.4-rc4
./mprotect -t 1           14ns		24ns
./mprotect -t 2           13ns		22ns
./mprotect -t 4           12ns		19ns
./mprotect -t 8           14ns		16ns
./mprotect -t 16          28ns		26ns
./mprotect -t 32          54ns		51ns
./mprotect -t 128         200ns		199ns

Single process with sequencial flushing and memory accessing:

		       	with patch   unpatched 3.4-rc4
./mprotect		    7ns			11ns
./mprotect -p 4096  -l 8 -n 10240
			    21ns		21ns

[ hpa: http://lkml.kernel.org/r/1B4B44D9196EFF41AE41FDA404FC0A100BFF94@SHSMSX101.ccr.corp.intel.com
  has additional performance numbers. ]
Signed-off-by: NAlex Shi <alex.shi@intel.com>
Link: http://lkml.kernel.org/r/1340845344-27557-3-git-send-email-alex.shi@intel.comSigned-off-by: NH. Peter Anvin <hpa@zytor.com>
      e7b52ffd
  47. 25 6月, 2012 3 次提交
    • C
      x86/uv: Work around UV2 BAU hangs · 8b6e511e
      由 Cliff Wickman 提交于 
      On SGI's UV2 the BAU (Broadcast Assist Unit) driver can hang
under a heavy load. To cure this:

- Disable the UV2 extended status mode (see UV2_EXT_SHFT), as
  this mode changes BAU behavior in more ways then just delivering
  an extra bit of status.  Revert status to just two meaningful bits,
  like UV1.

- Use no IPI-style resets on UV2.  Just give up the request for
  whatever the reason it failed and let it be accomplished with
  the legacy IPI method.

- Use no alternate sending descriptor (the former UV2 workaround
  bcp->using_desc and handle_uv2_busy() stuff).  Just disable the
  use of the BAU for a period of time in favor of the legacy IPI
  method when the h/w bug leaves a descriptor busy.

  -- new tunable: giveup_limit determines the threshold at which a hub is
     so plugged that it should do all requests with the legacy IPI method for a
     period of time
  -- generalize disable_for_congestion() (renamed disable_for_period()) for
     use whenever a hub should avoid using the BAU for a period of time

Also:

 - Fix find_another_by_swack(), which is part of the UV2 bug workaround

 - Correct and clarify the statistics (new stats s_overipilimit, s_giveuplimit,
   s_enters, s_ipifordisabled, s_plugged, s_congested)
Signed-off-by: NCliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120622131459.GC31884@sgi.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      8b6e511e
    • C
      x86/uv: Implement UV BAU runtime enable and disable control via /proc/sgi_uv/ · 26ef8577
      由 Cliff Wickman 提交于 
      This patch enables the BAU to be turned on or off dynamically.

  echo "on"  > /proc/sgi_uv/ptc_statistics
  echo "off" > /proc/sgi_uv/ptc_statistics

The system may be booted with or without the nobau option.

Whether the system currently has the BAU off can be seen in
the /proc file -- normally with the baustats script.
Each cpu will have a 1 in the bauoff field if the BAU was turned
off, so baustats will give a count of cpus that have it off.
Signed-off-by: NCliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120622131330.GB31884@sgi.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      26ef8577
    • C
      x86/uv: Fix the UV BAU destination timeout period · 11cab711
      由 Cliff Wickman 提交于 
      Correct the calculation of a destination timeout period, which
is used to distinguish between a destination timeout and the
situation where all the target software ack resources are full
and a request is returned immediately.

The problem is that integer arithmetic was overflowing, yielding
a very large result.

Without this fix destination timeouts are identified as resource
'plugged' events and an ipi method of resource releasing is
unnecessarily employed.
Signed-off-by: NCliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120622131212.GA31884@sgi.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      11cab711