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Date: Tue, 20 Oct 2009 17:29:16 +0100 From: Chris Wilson <chris@...is-wilson.co.uk> To: intel-gfx@...ts.freedesktop.org Cc: linux-kernel@...r.kernel.org, dri-devel@...ts.sourceforge.net, Chris Wilson <chris@...is-wilson.co.uk>, Miles Lane <miles.lane@...il.com> Subject: [PATCH] drm/i915: Avoid potential sleep whilst holding spinlock Miles Lane reported the following error: 2 locks held by cat/4179: #0: (&p->lock){+.+.+.}, at: [<c10a3884>] seq_read+0x25/0x315 #1: (&dev_priv->mm.active_list_lock){+.+...}, at: [<c119a854>] i915_batchbuffer_info+0x2b/0x124 Pid: 4179, comm: cat Not tainted 2.6.32-rc5-git1 #2 Call Trace: [<c104874f>] ? __debug_show_held_locks+0x1e/0x20 [<c1023fb0>] __might_sleep+0xf0/0xf7 [<c101c393>] kmap+0x17/0x58 [<c119a8d6>] i915_batchbuffer_info+0xad/0x124 [<c10a39bf>] seq_read+0x160/0x315 [<c108fb8c>] ? rw_verify_area+0x98/0xbb [<c10a385f>] ? seq_read+0x0/0x315 [<c1090331>] vfs_read+0x75/0xa9 [<c10903f9>] sys_read+0x3b/0x5d [<c1002a8f>] sysenter_do_call+0x12/0x36 The fix is relatively simple, use the atomic variants of kmap() that avoid the potential sleep. Signed-off-by: Chris Wilson <chris@...is-wilson.co.uk> Cc: Miles Lane <miles.lane@...il.com> --- drivers/gpu/drm/i915/i915_debugfs.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c index 2ace8b7..9087c4c 100644 --- a/drivers/gpu/drm/i915/i915_debugfs.c +++ b/drivers/gpu/drm/i915/i915_debugfs.c @@ -268,10 +268,10 @@ static void i915_dump_pages(struct seq_file *m, struct page **pages, int page_co uint32_t *mem; for (page = 0; page < page_count; page++) { - mem = kmap(pages[page]); + mem = kmap_atomic(pages[page], KM_USER0); for (i = 0; i < PAGE_SIZE; i += 4) seq_printf(m, "%08x : %08x\n", i, mem[i / 4]); - kunmap(pages[page]); + kunmap_atomic(pages[page], KM_USER0); } } -- 1.6.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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