lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Wed, 10 Apr 2019 09:53:25 +0800
From:   Aubrey Li <>
        Aubrey Li <>
Subject: [PATCH v14 3/3] Documentation/filesystems/proc.txt: add AVX512_elapsed_ms

Added AVX512_elapsed_ms in /proc/<pid>/status. Report it
in Documentation/filesystems/proc.txt

Signed-off-by: Aubrey Li <>
Cc: Peter Zijlstra <>
Cc: Andi Kleen <>
Cc: Tim Chen <>
Cc: Dave Hansen <>
Cc: Arjan van de Ven <>
Cc: Linux API <>
Cc: Alexey Dobriyan <>
Cc: Andrew Morton <>
 Documentation/filesystems/proc.txt | 29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index 66cad5c86171..c4a9e48681ad 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -207,6 +207,7 @@ read the file /proc/PID/status:
   Speculation_Store_Bypass:       thread vulnerable
   voluntary_ctxt_switches:        0
   nonvoluntary_ctxt_switches:     1
+  AVX512_elapsed_ms:	8
 This shows you nearly the same information you would get if you viewed it with
 the ps  command.  In  fact,  ps  uses  the  proc  file  system  to  obtain its
@@ -224,7 +225,7 @@ asynchronous manner and the value may not be very precise. To see a precise
 snapshot of a moment, you can see /proc/<pid>/smaps file and scan page table.
 It's slow but very precise.
-Table 1-2: Contents of the status files (as of 4.19)
+Table 1-2: Contents of the status files (as of 5.1)
  Field                       Content
  Name                        filename of the executable
@@ -289,6 +290,32 @@ Table 1-2: Contents of the status files (as of 4.19)
  Mems_allowed_list           Same as previous, but in "list format"
  voluntary_ctxt_switches     number of voluntary context switches
  nonvoluntary_ctxt_switches  number of non voluntary context switches
+ AVX512_elapsed_ms           time elapsed since last AVX512 usage recorded
+ AVX512_elapsed_ms:
+ ------------------
+  If AVX512 is supported on the machine, this entry shows the milliseconds
+  elapsed since the last time AVX512 usage was recorded. The recording
+  happens on a best effort basis when a task is scheduled out. This means
+  that the value depends on two factors:
+    1) The time which the task spent on the CPU without being scheduled
+       out. With CPU isolation and a single runnable task this can take
+       several seconds.
+    2) The time since the task was scheduled out last. Depending on the
+       reason for being scheduled out (time slice exhausted, syscall ...)
+       this can be arbitrary long time.
+  As a consequence the value cannot be considered precise and authoritative
+  information. The application which uses this information has to be aware
+  of the overall scenario on the system in order to determine whether a
+  task is a real AVX512 user or not.
+  A special value of '-1' indicates that no AVX512 usage was recorded, thus
+  the task is unlikely an AVX512 user, but depends on the workload and the
+  scheduling scenario, it also could be a false negative mentioned above.
 Table 1-3: Contents of the statm files (as of 2.6.8-rc3)

Powered by blists - more mailing lists