> So it's definitely in mainline, and its definitely > not Seto-san's patch. Here's the root of the problem (arch/ia64/kernel/entry.S): 1175 br.call.spnt.many rp=schedule 1176 .ret9: cmp.eq p6,p0=r0,r0 // p6 <- 1 1177 rsm psr.i // disable interrupts 1178 ;; 1179 #ifdef CONFIG_PREEMPT 1180 (pKStk) adds r20=TI_PRE_COUNT+IA64_TASK_SIZE,r13 1181 ;; 1182 (pKStk) st4 [r20]=r0 // preempt_count() <- 0 1183 #endif 1184 (pLvSys)br.cond.sptk.few .work_pending_syscall_end 1185 br.cond.sptk.many .work_processed_kernel // re-check 1186 1187 .notify: 1188 (pUStk) br.call.spnt.many rp=notify_resume_user on line 1188 we call notify_resume_user() with interrupts disabled (at least if we fall through from the code above ... I didn't check the state of interrupts if we branch to ".notify"). So we start down this call chain to the might_sleep() check: [<a000000100011bf0>] show_stack+0x50/0xa0 [<a000000100011c70>] dump_stack+0x30/0x60 [<a000000100061a90>] __might_sleep+0x1f0/0x220 [<a000000100709020>] down_read+0x20/0x60 [<a0000001000fe060>] access_process_vm+0x60/0x2c0 [<a00000010002a280>] ia64_sync_kernel_rbs+0x40/0x100 [<a00000010002a400>] do_sync_rbs+0xc0/0x100 [<a00000010000ac30>] unw_init_running+0x70/0xa0 [<a00000010002a5c0>] ia64_sync_krbs+0x80/0xa0 [<a000000100012690>] do_notify_resume_user+0x110/0x140 [<a00000010000aac0>] notify_resume_user+0x40/0x60 [<a00000010000a9f0>] skip_rbs_switch+0xe0/0x110 [<a000000000010740>] __kernel_syscall_via_break+0x0/0x20 -- To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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