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author | Ingo Molnar | 2015-03-04 06:35:43 +0100 |
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committer | Ingo Molnar | 2015-03-04 06:35:43 +0100 |
commit | d2c032e3dc58137a7261a7824d3acce435db1d66 (patch) | |
tree | 7eea1c7c6103eefe879f07472eec99b3c41eb792 /arch/nios2/mm/fault.c | |
parent | x86/compat: Remove sys32_vm86_warning (diff) | |
parent | Linux 4.0-rc2 (diff) | |
download | kernel-qcow2-linux-d2c032e3dc58137a7261a7824d3acce435db1d66.tar.gz kernel-qcow2-linux-d2c032e3dc58137a7261a7824d3acce435db1d66.tar.xz kernel-qcow2-linux-d2c032e3dc58137a7261a7824d3acce435db1d66.zip |
Merge tag 'v4.0-rc2' into x86/asm, to refresh the tree
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/nios2/mm/fault.c')
-rw-r--r-- | arch/nios2/mm/fault.c | 37 |
1 files changed, 32 insertions, 5 deletions
diff --git a/arch/nios2/mm/fault.c b/arch/nios2/mm/fault.c index d194c0427b26..0d231adfe576 100644 --- a/arch/nios2/mm/fault.c +++ b/arch/nios2/mm/fault.c @@ -47,7 +47,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long cause, struct mm_struct *mm = tsk->mm; int code = SEGV_MAPERR; int fault; - unsigned int flags = 0; + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; cause >>= 2; @@ -86,6 +86,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long cause, if (!down_read_trylock(&mm->mmap_sem)) { if (!user_mode(regs) && !search_exception_tables(regs->ea)) goto bad_area_nosemaphore; +retry: down_read(&mm->mmap_sem); } @@ -132,6 +133,10 @@ survive: * the fault. */ fault = handle_mm_fault(mm, vma, address, flags); + + if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) + return; + if (unlikely(fault & VM_FAULT_ERROR)) { if (fault & VM_FAULT_OOM) goto out_of_memory; @@ -141,10 +146,32 @@ survive: goto do_sigbus; BUG(); } - if (fault & VM_FAULT_MAJOR) - tsk->maj_flt++; - else - tsk->min_flt++; + + /* + * Major/minor page fault accounting is only done on the + * initial attempt. If we go through a retry, it is extremely + * likely that the page will be found in page cache at that point. + */ + if (flags & FAULT_FLAG_ALLOW_RETRY) { + if (fault & VM_FAULT_MAJOR) + current->maj_flt++; + else + current->min_flt++; + if (fault & VM_FAULT_RETRY) { + /* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk + * of starvation. */ + flags &= ~FAULT_FLAG_ALLOW_RETRY; + flags |= FAULT_FLAG_TRIED; + + /* + * No need to up_read(&mm->mmap_sem) as we would + * have already released it in __lock_page_or_retry + * in mm/filemap.c. + */ + + goto retry; + } + } up_read(&mm->mmap_sem); return; |