On Tue, Mar 11, 2014 at 07:32:34PM +0530, Ramakrishnan Muthukrishnan wrote: > Hello linux-mm hackers, > > We have a TI OMAP4 based system running 3.4 kernel. OMAP4 has got 2 M3 > processors which is used for some media tasks. > > During bootup, the M3 firmware is loaded and it used CMA to allocate 3 > regions for DMA, as seen by these logs: > > [ 0.000000] cma: dma_declare_contiguous(size a400000, base > 99000000, limit 00000000) > [ 0.000000] cma: CMA: reserved 168 MiB at 99000000 > [ 0.000000] cma: dma_declare_contiguous(size 2000000, base > 00000000, limit 00000000) > [ 0.000000] cma: CMA: reserved 32 MiB at ad800000 > [ 0.000000] cma: dma_contiguous_reserve(limit af800000) > [ 0.000000] cma: dma_contiguous_reserve: reserving 16 MiB for global area > [ 0.000000] cma: dma_declare_contiguous(size 1000000, base > 00000000, limit af800000) > [ 0.000000] cma: CMA: reserved 16 MiB at ac000000 > [ 0.243652] cma: cma_init_reserved_areas() > [ 0.243682] cma: cma_create_area(base 00099000, count a800) > [ 0.253417] cma: cma_create_area: returned ed0ee400 > [...] > > We observed that if we reboot a system without unmounting the file > systems (like in abrupt power off..etc), after the fresh reboot, the > file system checks are performed, the firmware load is delayed by ~4 > seconds (compared to the one without fsck) and then we see the > following in the kernel bootup logs: > > [ 26.846313] alloc_contig_range test_pages_isolated(a2e00, a3400) failed > [ 26.853515] alloc_contig_range test_pages_isolated(a2e00, a3500) failed > [ 26.860809] alloc_contig_range test_pages_isolated(a3100, a3700) failed > [ 26.868133] alloc_contig_range test_pages_isolated(a3200, a3800) failed > [ 26.875213] rproc remoteproc0: dma_alloc_coherent failed: 6291456 > [ 26.881744] rproc remoteproc0: Failed to process resources: -12 > [ 26.902221] omap_hwmod: ipu: failed to hardreset > [ 26.909545] omap_hwmod: ipu: _wait_target_disable failed > [ 26.916748] rproc remoteproc0: rproc_boot() failed -12 > > The M3 firmware load fails because of this. I have been looking at the > git logs to see if this is fixed in the later checkins, since this is > a bit old kernel. For various non-technical reasons which I have no > control of, we can't move to a newer kernel. But I could backport any > fixes done in newer kernel. Also I am totally new to memory management > in the kernel, so any help in debugging is highly appreciated. Hello, Is this log all? In the above log, test_pages_isolated() failed for a short time. Is it root cause of delayed firmware loading? Why "cma: dma_alloc_from_contiguous(): memory range at %p is busy, retrying" isn't appeared? There is possible race in start_isolate_page_range() and so on, so some pages in CMA region don't be moved to MIGRATE_ISOLATE list and test_pages_isolated() could fail. But, it doesn't last for a long time as far as I know. Thanks. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>