On Thu, 2018-05-10 at 12:28 +0200, Mike Galbraith wrote:> On Thu, 2018-05-10 at 11:10 +0200, Mike Galbraith wrote: > > Greetings, > > > > When box is earning its keep, nouveau/swiotlb grumble.. a LOT. The > > below is from master.today. > > > > [12594.640959] nouveau 0000:01:00.0: swiotlb buffer is full (sz: 2097152 bytes) > > [12594.693000] nouveau 0000:01:00.0: swiotlb buffer is full (sz: 2097152 bytes) > > [12594.713787] nouveau 0000:01:00.0: swiotlb buffer is full (sz: 2097152 bytes) > > [12594.743413] nouveau 0000:01:00.0: swiotlb buffer is full (sz: 2097152 bytes) > > [12594.796740] nouveau 0000:01:00.0: swiotlb buffer is full (sz: 2097152 bytes) > > [12607.000774] swiotlb_tbl_map_single: 54 callbacks suppressed > > [12607.000776] nouveau 0000:01:00.0: swiotlb buffer is full (sz: 2097152 bytes) > > [12607.347941] nouveau 0000:01:00.0: swiotlb buffer is full (sz: 2097152 bytes) > > [12608.677038] nouveau 0000:01:00.0: swiotlb buffer is full (sz: 2097152 bytes) > > homer:/novell/ssh # dmesg|grep 'swiotlb buffer is full'|wc -l > > 2052 > > homer:/novell/ssh # dmesg|grep 'callbacks suppressed'|wc -l > > 171 > > > > lib/swiotlb.c: > > 573 not_found: > > 574 spin_unlock_irqrestore(&io_tlb_lock, flags); > > 575 if (!(attrs & DMA_ATTR_NO_WARN) && printk_ratelimit()) > > 576 dev_warn(hwdev, "swiotlb buffer is full (sz: %zd bytes)\n", size); > > > > Does nouveau perhaps want one of those DMA_ATTR_NO_WARN thingies? > > Or should ttm perhaps always use the one on hand? (seems to work)No it didn't, I just didn't wait long enough for spew to start...> --- > drivers/gpu/drm/ttm/ttm_page_alloc_dma.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > --- a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c > +++ b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c > @@ -342,7 +342,7 @@ static struct dma_page *__ttm_dma_alloc_ > if (!d_page) > return NULL; > > - if (pool->type & IS_HUGE) > + if (1 || pool->type & IS_HUGE) > attrs = DMA_ATTR_NO_WARN; > > vaddr = dma_alloc_attrs(pool->dev, pool->size, &d_page->dma,While IS_HUGE is indeed false on my box, it just doesn't matter, because when we get to either the old or the new alloc(), it calls swiotlb_alloc_buffer(), which drops attrs passed to it on the floor, making it unlikely that alloc() caller wishes are granted. -Mike
Mike Galbraith
2018-May-11 15:15 UTC
[Nouveau] [patch] swiotlb: fix ignored DMA_ATTR_NO_WARN request
In the trace below, swiotlb_alloc() is called with __GFP_NOWARN, it ors attrs with DMA_ATTR_NO_WARN and passes it to swiotlb_alloc_buffer(), which does NOT pass it on to swiotlb_tbl_map_single(), leading to an ever repeating warning that the caller of swiotlb_alloc() explicitly asked to be squelched. Pass the caller's request for silence onward. Xorg-3170 [006] .... 963.866098: swiotlb_alloc+0x1d/0x1a0: gfp & __GFP_NOWARN Xorg-3170 [006] .... 963.866101: <stack trace> => ttm_dma_populate+0x250/0x310 [ttm] => ttm_tt_populate+0x28/0x70 [ttm] => ttm_tt_bind+0x26/0x60 [ttm] => ttm_bo_handle_move_mem+0x51a/0x580 [ttm] => ttm_bo_validate+0xfa/0x110 [ttm] => ttm_bo_init_reserved+0x296/0x450 [ttm] => ttm_bo_init+0x73/0xd0 [ttm] => nouveau_bo_new+0x3eb/0x5c0 [nouveau] => nouveau_gem_new+0x66/0x110 [nouveau] => nouveau_gem_ioctl_new+0x48/0xc0 [nouveau] => drm_ioctl_kernel+0x66/0xb0 [drm] => drm_ioctl+0x28d/0x340 [drm] => nouveau_drm_ioctl+0x50/0xb0 [nouveau] => do_vfs_ioctl+0x92/0x5e0 => ksys_ioctl+0x3a/0x70 => __x64_sys_ioctl+0x16/0x20 => do_syscall_64+0x5b/0x180 => entry_SYSCALL_64_after_hwframe+0x44/0xa9 Xorg-3170 [006] .... 963.866917: swiotlb_tbl_map_single+0x29b/0x2d0: swiotlb buffer is full (sz: 2097152 bytes) Signed-off-by: Mike Galbraith <efault at gmx.de> --- lib/swiotlb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -714,7 +714,7 @@ swiotlb_alloc_buffer(struct device *dev, phys_addr = swiotlb_tbl_map_single(dev, __phys_to_dma(dev, io_tlb_start), - 0, size, DMA_FROM_DEVICE, 0); + 0, size, DMA_FROM_DEVICE, attrs); if (phys_addr == SWIOTLB_MAP_ERROR) goto out_warn;
Mike Galbraith
2018-May-12 07:11 UTC
[Nouveau] [patch] swiotlb: fix ignored DMA_ATTR_NO_WARN request
To conclude to this snail like thread (/me=walking wounded), with the v4.16.8 hunk below, traces showing that swiotlb_alloc_coherent() was being asked to not bother warning started showing up after the box had been flogged for a while. Whatever finally happens with swiotlb (seems to be in flux), other folks meeting annoying gripeage can find bandaids in the interim. The End v4.16.8 !DMA_DIRECT_OPS Xorg-3105 [001] .... 2156.711471: swiotlb_alloc_coherent+0xa7/0x1e0: yup Xorg-3105 [001] .... 2156.711497: <stack trace> => ttm_dma_populate+0x23c/0x310 [ttm] => ttm_tt_bind+0x31/0x60 [ttm] => ttm_bo_handle_move_mem+0x527/0x580 [ttm] => ttm_bo_validate+0xfb/0x110 [ttm] => ttm_bo_init_reserved+0x289/0x450 [ttm] => ttm_bo_init+0x77/0xd0 [ttm] => nouveau_bo_new+0x3fc/0x5e0 [nouveau] => nouveau_gem_new+0x66/0x110 [nouveau] => nouveau_gem_ioctl_new+0x48/0xc0 [nouveau] => drm_ioctl_kernel+0x66/0xb0 [drm] => drm_ioctl+0x2a4/0x360 [drm] => nouveau_drm_ioctl+0x50/0xb0 [nouveau] => do_vfs_ioctl+0x92/0x5e0 => SyS_ioctl+0x3b/0x70 => do_syscall_64+0x74/0x1a0 => entry_SYSCALL_64_after_hwframe+0x3d/0xa2 --- a/arch/x86/kernel/pci-swiotlb.c +++ b/arch/x86/kernel/pci-swiotlb.c @@ -28,10 +28,8 @@ void *x86_swiotlb_alloc_coherent(struct * swiotlb_alloc_coherent() will print a warning when the DMA * memory allocation ultimately failed. */ - flags |= __GFP_NOWARN; - - vaddr = dma_generic_alloc_coherent(hwdev, size, dma_handle, flags, - attrs); + vaddr = dma_generic_alloc_coherent(hwdev, size, dma_handle, + flags | __GFP_NOWARN, attrs); if (vaddr) return vaddr;