* [PATCH 07/20] microblaze/mm/fault.c: Port OOM changes to do_page_fault
@ 2012-03-20 13:21 Kautuk Consul
2012-03-30 13:29 ` Michal Simek
0 siblings, 1 reply; 3+ messages in thread
From: Kautuk Consul @ 2012-03-20 13:21 UTC (permalink / raw)
To: Michal Simek; +Cc: microblaze-uclinux, linux-kernel, Kautuk Consul
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 microblaze.
Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com>
---
arch/microblaze/mm/fault.c | 33 ++++++++++++++++++++++++++++-----
1 files changed, 28 insertions(+), 5 deletions(-)
diff --git a/arch/microblaze/mm/fault.c b/arch/microblaze/mm/fault.c
index ae97d2c..60e19e6 100644
--- a/arch/microblaze/mm/fault.c
+++ b/arch/microblaze/mm/fault.c
@@ -93,6 +93,8 @@ void do_page_fault(struct pt_regs *regs, unsigned long address,
int code = SEGV_MAPERR;
int is_write = error_code & ESR_S;
int fault;
+ unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE |
+ (is_write ? FAULT_FLAG_WRITE : 0);
regs->ear = address;
regs->esr = error_code;
@@ -139,6 +141,7 @@ void do_page_fault(struct pt_regs *regs, unsigned long address,
if (kernel_mode(regs) && !search_exception_tables(regs->pc))
goto bad_area_nosemaphore;
+retry:
down_read(&mm->mmap_sem);
}
@@ -211,7 +214,11 @@ good_area:
* make sure we exit gracefully rather than endlessly redo
* the fault.
*/
- fault = handle_mm_fault(mm, vma, address, is_write ? FAULT_FLAG_WRITE : 0);
+ 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;
@@ -219,11 +226,27 @@ good_area:
goto do_sigbus;
BUG();
}
- if (unlikely(fault & VM_FAULT_MAJOR))
- current->maj_flt++;
- else
- current->min_flt++;
+
+ if (flags & FAULT_FLAG_ALLOW_RETRY) {
+ if (unlikely(fault & VM_FAULT_MAJOR))
+ current->maj_flt++;
+ else
+ current->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;
+ }
+ }
+
up_read(&mm->mmap_sem);
+
/*
* keep track of tlb+htab misses that are good addrs but
* just need pte's created via handle_mm_fault()
--
1.7.5.4
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH 07/20] microblaze/mm/fault.c: Port OOM changes to do_page_fault
2012-03-20 13:21 [PATCH 07/20] microblaze/mm/fault.c: Port OOM changes to do_page_fault Kautuk Consul
@ 2012-03-30 13:29 ` Michal Simek
2012-03-31 10:09 ` Kautuk Consul
0 siblings, 1 reply; 3+ messages in thread
From: Michal Simek @ 2012-03-30 13:29 UTC (permalink / raw)
To: Kautuk Consul; +Cc: microblaze-uclinux, linux-kernel
On 03/20/2012 02:21 PM, 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 microblaze.
>
> Signed-off-by: Kautuk Consul<consul.kautuk@gmail.com>
> ---
> arch/microblaze/mm/fault.c | 33 ++++++++++++++++++++++++++++-----
> 1 files changed, 28 insertions(+), 5 deletions(-)
>
> diff --git a/arch/microblaze/mm/fault.c b/arch/microblaze/mm/fault.c
> index ae97d2c..60e19e6 100644
> --- a/arch/microblaze/mm/fault.c
> +++ b/arch/microblaze/mm/fault.c
> @@ -93,6 +93,8 @@ void do_page_fault(struct pt_regs *regs, unsigned long address,
> int code = SEGV_MAPERR;
> int is_write = error_code& ESR_S;
> int fault;
> + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE |
> + (is_write ? FAULT_FLAG_WRITE : 0);
>
> regs->ear = address;
> regs->esr = error_code;
> @@ -139,6 +141,7 @@ void do_page_fault(struct pt_regs *regs, unsigned long address,
> if (kernel_mode(regs)&& !search_exception_tables(regs->pc))
> goto bad_area_nosemaphore;
>
> +retry:
> down_read(&mm->mmap_sem);
> }
>
> @@ -211,7 +214,11 @@ good_area:
> * make sure we exit gracefully rather than endlessly redo
> * the fault.
> */
> - fault = handle_mm_fault(mm, vma, address, is_write ? FAULT_FLAG_WRITE : 0);
> + 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;
> @@ -219,11 +226,27 @@ good_area:
> goto do_sigbus;
> BUG();
> }
> - if (unlikely(fault& VM_FAULT_MAJOR))
> - current->maj_flt++;
> - else
> - current->min_flt++;
> +
> + if (flags& FAULT_FLAG_ALLOW_RETRY) {
> + if (unlikely(fault& VM_FAULT_MAJOR))
> + current->maj_flt++;
> + else
> + current->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;
> + }
> + }
> +
> up_read(&mm->mmap_sem);
> +
> /*
> * keep track of tlb+htab misses that are good addrs but
> * just need pte's created via handle_mm_fault()
it is fine.
Acked-by: Michal Simek <monstr@monstr.eu>
If this patch should go through my tree, please let me know.
Thanks,
Michal
--
Michal Simek, Ing. (M.Eng)
w: www.monstr.eu p: +42-0-721842854
Maintainer of Linux kernel 2.6 Microblaze Linux - http://www.monstr.eu/fdt/
Microblaze U-BOOT custodian
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH 07/20] microblaze/mm/fault.c: Port OOM changes to do_page_fault
2012-03-30 13:29 ` Michal Simek
@ 2012-03-31 10:09 ` Kautuk Consul
0 siblings, 0 replies; 3+ messages in thread
From: Kautuk Consul @ 2012-03-31 10:09 UTC (permalink / raw)
To: monstr; +Cc: microblaze-uclinux, linux-kernel
>
>
> it is fine.
>
> Acked-by: Michal Simek <monstr@monstr.eu>
Thanks, Michal.
>
> If this patch should go through my tree, please let me know.
Okay.
If I can't find anyone to take it, I will ping you.
At the moment, I am trying to get it applied via the -mm branch.
Thanks again.
>
> Thanks,
>
> Michal
>
>
>
> --
> Michal Simek, Ing. (M.Eng)
> w: www.monstr.eu p: +42-0-721842854
> Maintainer of Linux kernel 2.6 Microblaze Linux - http://www.monstr.eu/fdt/
> Microblaze U-BOOT custodian
^ permalink raw reply [flat|nested] 3+ messages in thread
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2012-03-20 13:21 [PATCH 07/20] microblaze/mm/fault.c: Port OOM changes to do_page_fault Kautuk Consul
2012-03-30 13:29 ` Michal Simek
2012-03-31 10:09 ` Kautuk Consul
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