Batch Queue Manager and database lock.

[Gilles Caulier]

2017-08-13 8:40 GMT+02:00 Maik Qualmann <metzpinguin at gmail.com>:
> Yes, the number of threads we use applies to all instances. We should always
> use all CPU cores. In BQM it makes no sense to limit it to a CPU core. Where
> was the problem in the maintenance tool?

Your patches do not compile with Qt 5.6 LTS:

[ 39%] Building CXX object
core/libs/threads/CMakeFiles/dthread_src.dir/actionthreadbase.cpp.o
/mnt/data/GIT/5.x/core/libs/threads/actionthreadbase.cpp: In member
function ‘void Digikam::ActionThreadBase::cancel()’:
/mnt/data/GIT/5.x/core/libs/threads/actionthreadbase.cpp:177:18:
error: ‘class QThreadPool’ has no member named ‘tryTake’
        d->pool->tryTake(job);
                 ^
core/libs/threads/CMakeFiles/dthread_src.dir/build.make:62: recipe for
target 'core/libs/threads/CMakeFiles/dthread_src.dir/action
threadbase.cpp.o' failed

Using one CPU core make a sence everywhere. in BQM, if you use
multicore (8 for ex on my host computer) you will run 8 BQM task at
the same time. The memory allocation can be huge, depending of image
sizes to process. If all memory is allocated, DK will crash.

There is an entry in bugzilla if i remember, to be more intelligent
with cpu cores to handle, depending of system resources available.

The problem is exactly the same with Maintenance tools.

and also, the problem is more critical with 32 bits OS where memory
avaialble is limited to 4Gb, where 1Gb is typically already reserved
for the OS.

Gilles