Hello, Am 28.02.17 um 11:04 schrieb Thomas Petazzoni: > Hello, > > On Sun, 26 Feb 2017 18:14:42 +0100, Johannes Thoma wrote: > >> As you pointed out the solution would be to allocate the memory earlier in the >> boot process, by modifying the driver. I will try that in the next few days and >> let you know the result. > > The whole point of CMA is that allocating earlier in the boot process > should not be necessary. CMA guarantees that the memory reserved for > the CMA pool is "movable", i.e it can be discarded when a CMA > allocation is done. > Yes it is moveable, but it takes rather long until it is moved (up to 20 Seconds). To test this I've implemented a loop that restarts from beginning of the CMA area as long as alloc_contig_range() returns -EBUSY (something similar to https://www.mail-archive.com/kernelnewbies@xxxxxxxxxxxxxxxxx/msg16956.html ). The result (on my system, which is an ARM based IMX-6 SOC) is that after some while it always succeeds but it takes some time. > So if a CMA allocation fails, I would rather suggest that the size of > your CMA pool is not large enough. Check your Device Tree and/or kernel > command (you can specify the size of the CMA pool on both if I remember > correctly). > We use kernel command line to set the CMA size, so I will try as you suggested. Thanks a lot, - Johannes _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
