On Tue, 2012-03-20 at 12:01 -0400, Kautuk Consul wrote: > Commit d065bd810b6deb67d4897a14bfe21f8eb526ba99 > (mm: retry page fault when blocking on disk transfer) and > commit 37b23e0525d393d48a7d59f870b3bc061a30ccdb > (x86,mm: make pagefault killable) > > The above commits introduced changes into the x86 pagefault handler > for making the page fault handler retryable as well as killable. > > These changes reduce the mmap_sem hold time, which is crucial > during OOM killer invocation. > > Port these changes to powerpc.
I have done that port already :-) It's in powerpc-next which I will send to Linus to pull today or tomorrow.... Cheers, Ben. > Signed-off-by: Mohd. Faris <[email protected]> > Signed-off-by: Kautuk Consul <[email protected]> > --- > arch/powerpc/mm/fault.c | 51 +++++++++++++++++++++++++++++++++------------- > 1 files changed, 36 insertions(+), 15 deletions(-) > > diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c > index 2f0d1b0..a3b1176 100644 > --- a/arch/powerpc/mm/fault.c > +++ b/arch/powerpc/mm/fault.c > @@ -129,6 +129,7 @@ int __kprobes do_page_fault(struct pt_regs *regs, > unsigned long address, > int is_write = 0, ret; > int trap = TRAP(regs); > int is_exec = trap == 0x400; > + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; > > #if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE)) > /* > @@ -212,6 +213,7 @@ int __kprobes do_page_fault(struct pt_regs *regs, > unsigned long address, > if (!user_mode(regs) && !search_exception_tables(regs->nip)) > goto bad_area_nosemaphore; > > +retry: > down_read(&mm->mmap_sem); > } > > @@ -313,6 +315,7 @@ good_area: > } else if (is_write) { > if (!(vma->vm_flags & VM_WRITE)) > goto bad_area; > + flags |= FAULT_FLAG_WRITE; > /* a read */ > } else { > /* protection fault */ > @@ -327,7 +330,11 @@ good_area: > * make sure we exit gracefully rather than endlessly redo > * the fault. > */ > - ret = handle_mm_fault(mm, vma, address, is_write ? FAULT_FLAG_WRITE : > 0); > + ret = handle_mm_fault(mm, vma, address, flags); > + > + if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) > + return 0; > + > if (unlikely(ret & VM_FAULT_ERROR)) { > if (ret & VM_FAULT_OOM) > goto out_of_memory; > @@ -335,22 +342,36 @@ good_area: > goto do_sigbus; > BUG(); > } > - if (ret & VM_FAULT_MAJOR) { > - current->maj_flt++; > - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, > - regs, address); > -#ifdef CONFIG_PPC_SMLPAR > - if (firmware_has_feature(FW_FEATURE_CMO)) { > - preempt_disable(); > - get_lppaca()->page_ins += (1 << PAGE_FACTOR); > - preempt_enable(); > + if (flags & FAULT_FLAG_ALLOW_RETRY) { > + if (ret & VM_FAULT_MAJOR) { > + current->maj_flt++; > + perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, > + regs, address); > +#ifdef CONFIG_PPC_SMLPAR > + if (firmware_has_feature(FW_FEATURE_CMO)) { > + preempt_disable(); > + get_lppaca()->page_ins += (1 << PAGE_FACTOR); > + preempt_enable(); > + } > +#endif > + } else { > + current->min_flt++; > + perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, > + regs, address); > + } > + if (fault & VM_FAULT_RETRY) { > + flags &= ~FAULT_FLAG_ALLOW_RETRY; > + > + /* > + * 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; > } > -#endif > - } else { > - current->min_flt++; > - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, > - regs, address); > } > + > up_read(&mm->mmap_sem); > return 0; > _______________________________________________ Linuxppc-dev mailing list [email protected] https://lists.ozlabs.org/listinfo/linuxppc-dev
