Commit Graph

8 Commits

Author SHA1 Message Date
Earl Ou
429b828e7b base: use setjmp to speed up fiber
ucontext is an order of magnitude slower compared to most of the fiber
implementation, mainly due to the additional signal mask operation.

This change applies the trick provided in
http://www.1024cores.net/home/lock-free-algorithms/tricks/fibers,
which uses _setjmp/_longjmp to switch between contexts created by
ucontext.

Combine with NodeList improvement, we see 81% speed improvement with the
example provided by Matthias Jung:
https://gist.github.com/myzinsky/557200aa04556de44a317e0a10f51840

Compared with Accellera's SystemC, gem5 SystemC was originally 10x
slower, and with this change it's about 1.8x.

Change-Id: I0ffb6978e83dc8be049b750dc1baebb3d251601c
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/34356
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
2020-09-16 07:57:40 +00:00
Hoa Nguyen
2ab4edcdfe base: Tag API methods and variables in fiber.hh
Change-Id: I586183426c8c56929a4640b0a985b4ddbf48c21f
Signed-off-by: Hoa Nguyen <hoanguyen@ucdavis.edu>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/33054
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
2020-09-08 16:22:29 +00:00
Gabe Black
d60d32ff26 base: Delete authors lists from files in base.
Change-Id: I73020efd522489ee152af890ab5e03449bc0a900
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/25415
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
2020-02-17 10:05:59 +00:00
Giacomo Travaglini
21573956f7 base: Provide a getter for Fiber::started boolean variable
This can be used to check if the fiber has started its execution.

Change-Id: Ie9222b8076756363c9f82c1333c76a352bcaf817
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18648
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
2019-06-09 11:03:04 +00:00
Gabe Black
5bfde967dc base: Set up a guard page for fiber stacks.
This will help detect stack overflow for fibers.

Change-Id: Iff2b102120ec351709e495291d6bead597f8d10c
Reviewed-on: https://gem5-review.googlesource.com/c/14395
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Gabe Black <gabeblack@google.com>
2018-11-18 10:44:26 +00:00
Gabe Black
a3385dadcb base: If valgrind is available, tell it about Fiber stacks.
Valgrind can get confused when  switching stacks between different
Fibers. If valgrind (and its headers) are available, this change adds
calls to some hooks so valgrind knows where the new stacks are and
doesn't report a bunch of false positives.

Change-Id: I00aefe60372be6de7371dec29427d7182dbee7b6
Reviewed-on: https://gem5-review.googlesource.com/12227
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Gabe Black <gabeblack@google.com>
2018-08-24 18:15:09 +00:00
Giacomo Travaglini
25f467ed78 base: Fix ucontext compilation error for macOS
ucontext functions (like getcontext, setcontext etc) have been marked
as deprecated and are hence hidden in latest macOS releases.
This patch uncovers them; warnings wil be produced but compilation
won't fail since -Wno-error=deprecated-declarations flag is currently
used.

Change-Id: Ic10e6f77a38875828b1891eaed2f0626ecffff67
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/11729
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
2018-07-26 07:00:34 +00:00
Gabe Black
3ed0c3c0be base: Add a class which encapsulates Fibers.
This class encapsulates the idea of a Fiber in such a way that other
implementations can be substituted in in the future. This
implementation uses the ucontext family of functions.

This change also adds a new unit test which exercises the new class. It
creates three new fibers which accept a sequence of other fibers to
switch to, one after the other. The main test function switches to
the these fibers which switch with each other and occasionally back to
the main fiber. Each time a test fiber is activated, it checks against
a list which shows the correct order for the fibers to run in. When the
main fiber gets control, it makes sure that list has been progressed
through by the correct amount.

Change-Id: I1fc2afa414b51baaa91e350a4ebc791d989f0b8a
Reviewed-on: https://gem5-review.googlesource.com/10935
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Gabe Black <gabeblack@google.com>
2018-06-21 19:13:43 +00:00