Messages in this thread | | | Date | Tue, 20 Mar 2012 12:09:30 -0400 | Subject | Re: [PATCH 16/20] tile/mm/fault.c: Port OOM changes to handle_page_fault | From | Kautuk Consul <> |
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hi,
There is a defect in this patch.
So, Ill post a v2 to this right away.
On Tue, Mar 20, 2012 at 9:26 AM, Kautuk Consul <consul.kautuk@gmail.com> 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 tile. > > Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com> > --- > arch/tile/mm/fault.c | 31 ++++++++++++++++++++++++++----- > 1 files changed, 26 insertions(+), 5 deletions(-) > > diff --git a/arch/tile/mm/fault.c b/arch/tile/mm/fault.c > index c1eaaa1..a097631 100644 > --- a/arch/tile/mm/fault.c > +++ b/arch/tile/mm/fault.c > @@ -267,6 +267,8 @@ static int handle_page_fault(struct pt_regs *regs, > int si_code; > int is_kernel_mode; > pgd_t *pgd; > + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE | > + (write ? FAULT_FLAG_WRITE : 0); > > /* on TILE, protection faults are always writes */ > if (!is_page_fault) > @@ -373,6 +375,8 @@ static int handle_page_fault(struct pt_regs *regs, > vma = NULL; /* happy compiler */ > goto bad_area_nosemaphore; > } > + > +retry: > down_read(&mm->mmap_sem); > } > > @@ -420,7 +424,11 @@ good_area: > * make sure we exit gracefully rather than endlessly redo > * the fault. > */ > - fault = handle_mm_fault(mm, vma, address, write); > + fault = handle_mm_fault(mm, vma, address, flags); > + > + if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) > + return;
Incorrect! This function returns an int.
> + > if (unlikely(fault & VM_FAULT_ERROR)) { > if (fault & VM_FAULT_OOM) > goto out_of_memory; > @@ -428,10 +436,23 @@ good_area: > goto do_sigbus; > BUG(); > } > - if (fault & VM_FAULT_MAJOR) > - tsk->maj_flt++; > - else > - tsk->min_flt++; > + if (flags & FAULT_FLAG_ALLOW_RETRY) { > + if (fault & VM_FAULT_MAJOR) > + tsk->maj_flt++; > + else > + tsk->min_flt++; > + 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; > + } > + } > > #if CHIP_HAS_TILE_DMA() || CHIP_HAS_SN_PROC() > /* > -- > 1.7.5.4 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.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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