On 20-05-28 08:19:46, Belisko Marek wrote: > Hi, > > we're using USB RAW gadget for communicating with PC application. We > have created loopback test which send file (any size) from PC to > device and then same data are sent back to PC to verify roundtrip time > (using bulk data transfer). Everything works fine up to 3MB file size. > If we sent bigger file like e.g. 5M we can receive file on device but > when we want to write to output endpoint we got: > > WARNING: CPU: 0 PID: 12299 at /kernel-source//mm/page_alloc.c:3725 > __alloc_pages_nodemask+0x1b0/0xde4 > [<c010fa08>] (unwind_backtrace) from [<c010c45c>] (show_stack+0x20/0x24) > [<c010c45c>] (show_stack) from [<c04cc0d4>] (dump_stack+0x20/0x28) > [<c04cc0d4>] (dump_stack) from [<c01324ac>] (__warn+0xec/0x108) > [<c01324ac>] (__warn) from [<c0132598>] (warn_slowpath_null+0x30/0x38) > [<c0132598>] (warn_slowpath_null) from [<c021ccb8>] > (__alloc_pages_nodemask+0x1b0/0xde4) > [<c021ccb8>] (__alloc_pages_nodemask) from [<c023b888>] > (kmalloc_order+0x2c/0x48) > [<c023b888>] (kmalloc_order) from [<c023b8d0>] (kmalloc_order_trace+0x2c/0xd4) > [<c023b8d0>] (kmalloc_order_trace) from [<c0261c24>] (__kmalloc+0x40/0x264) > [<c0261c24>] (__kmalloc) from [<bf039bc4>] (ffs_epfile_io+0x13c/0x570 > [usb_f_fs]) > [<bf039bc4>] (ffs_epfile_io [usb_f_fs]) from [<bf03a0c0>] > (ffs_epfile_write_iter+0xc8/0x120 [usb_f_fs]) > [<bf03a0c0>] (ffs_epfile_write_iter [usb_f_fs]) from [<c02734bc>] > (new_sync_write+0xc8/0xec) > [<c02734bc>] (new_sync_write) from [<c027351c>] (__vfs_write+0x3c/0x48) > [<c027351c>] (__vfs_write) from [<c02749a0>] (vfs_write+0xcc/0x158) > [<c02749a0>] (vfs_write) from [<c02756ac>] (SyS_write+0x50/0x88) > [<c02756ac>] (SyS_write) from [<c0107a20>] (ret_fast_syscall+0x0/0x54) > ---[ end trace fe5f79fe415b9881 ]--- > > and write ends up with: write /run/ffs/ep1: cannot allocate memory > > When checked free command there should be plenty of available memory. > Is there some limitation when writing to endpoint? We tried to split > buffer to e.g. 3M and sent it and this works but looks like there is > penalty when sending bigger files (100MB file received in 5secs whicle > sending back it took 2minutes). Thanks for ideas and hints. > Although you see there are plenty of available memory, but the block number for the size(eg 64KB) you request may be zero. Since you use old kernel, the f_fs doesn't support scatter list. To fix it, you may use small buffer at use space, eg: 16KB per transfer. -- Thanks, Peter Chen
