diff options
Diffstat (limited to 'arch/tile/mm/fault.c')
| -rw-r--r-- | arch/tile/mm/fault.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/tile/mm/fault.c b/arch/tile/mm/fault.c index 0011f06b4fe..704f3e8a438 100644 --- a/arch/tile/mm/fault.c +++ b/arch/tile/mm/fault.c @@ -567,6 +567,14 @@ do_sigbus: * since that might indicate we have not yet squirreled the SPR * contents away and can thus safely take a recursive interrupt. * Accordingly, the hypervisor passes us the PC via SYSTEM_SAVE_1_2. + * + * Note that this routine is called before homecache_tlb_defer_enter(), + * which means that we can properly unlock any atomics that might + * be used there (good), but also means we must be very sensitive + * to not touch any data structures that might be located in memory + * that could migrate, as we could be entering the kernel on a dataplane + * cpu that has been deferring kernel TLB updates. This means, for + * example, that we can't migrate init_mm or its pgd. */ struct intvec_state do_page_fault_ics(struct pt_regs *regs, int fault_num, unsigned long address, |