Hi! > Motivates and explains the ktask API for kernel clients. > > Signed-off-by: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx> > --- > Documentation/core-api/index.rst | 1 + > Documentation/core-api/ktask.rst | 213 +++++++++++++++++++++++++++++++ > 2 files changed, 214 insertions(+) > create mode 100644 Documentation/core-api/ktask.rst > > diff --git a/Documentation/core-api/index.rst b/Documentation/core-api/index.rst > index 3adee82be311..c143a280a5b1 100644 > --- a/Documentation/core-api/index.rst > +++ b/Documentation/core-api/index.rst > @@ -18,6 +18,7 @@ Core utilities > refcount-vs-atomic > cpu_hotplug > idr > + ktask > local_ops > workqueue > genericirq > diff --git a/Documentation/core-api/ktask.rst b/Documentation/core-api/ktask.rst > new file mode 100644 > index 000000000000..c3c00e1f802f > --- /dev/null > +++ b/Documentation/core-api/ktask.rst > @@ -0,0 +1,213 @@ > +.. SPDX-License-Identifier: GPL-2.0+ > + > +============================================ > +ktask: parallelize CPU-intensive kernel work > +============================================ > + > +:Date: November, 2018 > +:Author: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx> > +For example, consider the task of clearing a gigantic page. This used to be > +done in a single thread with a for loop that calls a page clearing function for > +each constituent base page. To parallelize with ktask, the client first moves > +the for loop to the thread function, adapting it to operate on the range passed > +to the function. In this simple case, the thread function's start and end > +arguments are just addresses delimiting the portion of the gigantic page to > +clear. Then, where the for loop used to be, the client calls into ktask with > +the start address of the gigantic page, the total size of the gigantic page, > +and the thread function. Internally, ktask will divide the address range into > +an appropriate number of chunks and start an appropriate number of threads to > +complete these chunks. Great, so my little task is bound to CPUs 1-4 and uses gigantic pages. Kernel clears them for me. a) Do all the CPUs work for me, or just CPUs I was assigned to? b) Will my time my_little_task show the system time including the worker threads? Best regards, Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
Attachment:
signature.asc
Description: Digital signature
