* [PATCH] mm/msync: tweak tmpfs patch for syscall msync
@ 2012-04-25 10:06 Kang Kai
2012-04-25 13:47 ` Bruce Ashfield
0 siblings, 1 reply; 6+ messages in thread
From: Kang Kai @ 2012-04-25 10:06 UTC (permalink / raw)
To: bruce.ashfield; +Cc: yocto
Commit 1c3ae5441 fixes MIPS CPU cache alias problem. But it makes
posix test cases mlockall/3-6 3-7 fail.
Tweak the patch to:
1 check the vma and its flags first
2 don't quit the function when meet first vma belongs to tmpfs file
Signed-off-by: Kang Kai <kai.kang@windriver.com>
---
mm/msync.c | 30 +++++++++++++-----------------
1 files changed, 13 insertions(+), 17 deletions(-)
diff --git a/mm/msync.c b/mm/msync.c
index ced6215..31cd311 100644
--- a/mm/msync.c
+++ b/mm/msync.c
@@ -60,23 +60,6 @@ SYSCALL_DEFINE3(msync, unsigned long, start, size_t, len, int, flags)
down_read(&mm->mmap_sem);
vma = find_vma(mm, start);
-#ifdef CONFIG_TMPFS
- /*
- * For tmpfs, no matter which flag(ASYNC or SYNC) gets from msync,
- * there is not so much thing to do for CPUs without cache alias,
- * But for some CPUs with cache alias, msync has to flush cache
- * explicitly, which makes sure the data coherency between memory
- * file and cache.
- */
- file = vma->vm_file;
- if (file && (file->f_op == &shmem_file_operations)) {
- if(CPU_HAS_CACHE_ALIAS)
- flush_cache_range(vma, start, start+len);
- error = 0;
- goto out_unlock;
- }
-#endif
-
for (;;) {
/* Still start < end. */
@@ -97,6 +80,19 @@ SYSCALL_DEFINE3(msync, unsigned long, start, size_t, len, int, flags)
goto out_unlock;
}
file = vma->vm_file;
+#ifdef CONFIG_TMPFS
+ /*
+ * For tmpfs, no matter which flag(ASYNC or SYNC) gets from msync,
+ * there is not so much thing to do for CPUs without cache alias,
+ * But for some CPUs with cache alias, msync has to flush cache
+ * explicitly, which makes sure the data coherency between memory
+ * file and cache.
+ */
+ if (file && (file->f_op == &shmem_file_operations)) {
+ if(CPU_HAS_CACHE_ALIAS)
+ flush_cache_range(vma, start, start+len);
+ }
+#endif
start = vma->vm_end;
if ((flags & MS_SYNC) && file &&
(vma->vm_flags & VM_SHARED)) {
--
1.7.5.4
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] mm/msync: tweak tmpfs patch for syscall msync
2012-04-25 10:06 [PATCH] mm/msync: tweak tmpfs patch for syscall msync Kang Kai
@ 2012-04-25 13:47 ` Bruce Ashfield
2012-04-26 0:59 ` Zumeng Chen
0 siblings, 1 reply; 6+ messages in thread
From: Bruce Ashfield @ 2012-04-25 13:47 UTC (permalink / raw)
To: Kang Kai; +Cc: yocto
On 12-04-25 06:06 AM, Kang Kai wrote:
> Commit 1c3ae5441 fixes MIPS CPU cache alias problem. But it makes
Put a short log after the commit ID, that way we can read what the
old commit was trying to do right in this commit.
> posix test cases mlockall/3-6 3-7 fail.
Can we expand on what the test is doing ? That way the commit
header is stand alone. I know that I haven't memorized what all the
posix tests do :)
> Tweak the patch to:
> 1 check the vma and its flags first
Can you expand here as well. Do you really mean that you've moved
the CONFIG_TMPFS block down in the function so that the normal
vma flag checking will occur ?
> 2 don't quit the function when meet first vma belongs to tmpfs file
And for this part, can you (or Zumeng) explain why we used to need
to exit immediately and now we don't ?
The patch looks good though, thanks for looking into this tricky
area of code.
Cheers,
Bruce
>
> Signed-off-by: Kang Kai<kai.kang@windriver.com>
> ---
> mm/msync.c | 30 +++++++++++++-----------------
> 1 files changed, 13 insertions(+), 17 deletions(-)
>
> diff --git a/mm/msync.c b/mm/msync.c
> index ced6215..31cd311 100644
> --- a/mm/msync.c
> +++ b/mm/msync.c
> @@ -60,23 +60,6 @@ SYSCALL_DEFINE3(msync, unsigned long, start, size_t, len, int, flags)
> down_read(&mm->mmap_sem);
> vma = find_vma(mm, start);
>
> -#ifdef CONFIG_TMPFS
> - /*
> - * For tmpfs, no matter which flag(ASYNC or SYNC) gets from msync,
> - * there is not so much thing to do for CPUs without cache alias,
> - * But for some CPUs with cache alias, msync has to flush cache
> - * explicitly, which makes sure the data coherency between memory
> - * file and cache.
> - */
> - file = vma->vm_file;
> - if (file&& (file->f_op ==&shmem_file_operations)) {
> - if(CPU_HAS_CACHE_ALIAS)
> - flush_cache_range(vma, start, start+len);
> - error = 0;
> - goto out_unlock;
> - }
> -#endif
> -
> for (;;) {
>
> /* Still start< end. */
> @@ -97,6 +80,19 @@ SYSCALL_DEFINE3(msync, unsigned long, start, size_t, len, int, flags)
> goto out_unlock;
> }
> file = vma->vm_file;
> +#ifdef CONFIG_TMPFS
> + /*
> + * For tmpfs, no matter which flag(ASYNC or SYNC) gets from msync,
> + * there is not so much thing to do for CPUs without cache alias,
> + * But for some CPUs with cache alias, msync has to flush cache
> + * explicitly, which makes sure the data coherency between memory
> + * file and cache.
> + */
> + if (file&& (file->f_op ==&shmem_file_operations)) {
> + if(CPU_HAS_CACHE_ALIAS)
> + flush_cache_range(vma, start, start+len);
> + }
> +#endif
> start = vma->vm_end;
> if ((flags& MS_SYNC)&& file&&
> (vma->vm_flags& VM_SHARED)) {
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] mm/msync: tweak tmpfs patch for syscall msync
2012-04-25 13:47 ` Bruce Ashfield
@ 2012-04-26 0:59 ` Zumeng Chen
2012-04-26 1:15 ` Bruce Ashfield
0 siblings, 1 reply; 6+ messages in thread
From: Zumeng Chen @ 2012-04-26 0:59 UTC (permalink / raw)
To: Bruce Ashfield; +Cc: yocto
That was my last version, you can google to get by "msync zumeng"
So feel free to merge it.
Regards,
Zumeng
于 2012年04月25日 21:47, Bruce Ashfield 写道:
> On 12-04-25 06:06 AM, Kang Kai wrote:
>> Commit 1c3ae5441 fixes MIPS CPU cache alias problem. But it makes
>
> Put a short log after the commit ID, that way we can read what the
> old commit was trying to do right in this commit.
>
>> posix test cases mlockall/3-6 3-7 fail.
>
> Can we expand on what the test is doing ? That way the commit
> header is stand alone. I know that I haven't memorized what all the
> posix tests do :)
>
>> Tweak the patch to:
>> 1 check the vma and its flags first
>
> Can you expand here as well. Do you really mean that you've moved
> the CONFIG_TMPFS block down in the function so that the normal
> vma flag checking will occur ?
>
>> 2 don't quit the function when meet first vma belongs to tmpfs file
>
> And for this part, can you (or Zumeng) explain why we used to need
> to exit immediately and now we don't ?
>
> The patch looks good though, thanks for looking into this tricky
> area of code.
>
> Cheers,
>
> Bruce
>
>>
>> Signed-off-by: Kang Kai<kai.kang@windriver.com>
>> ---
>> mm/msync.c | 30 +++++++++++++-----------------
>> 1 files changed, 13 insertions(+), 17 deletions(-)
>>
>> diff --git a/mm/msync.c b/mm/msync.c
>> index ced6215..31cd311 100644
>> --- a/mm/msync.c
>> +++ b/mm/msync.c
>> @@ -60,23 +60,6 @@ SYSCALL_DEFINE3(msync, unsigned long, start,
>> size_t, len, int, flags)
>> down_read(&mm->mmap_sem);
>> vma = find_vma(mm, start);
>>
>> -#ifdef CONFIG_TMPFS
>> - /*
>> - * For tmpfs, no matter which flag(ASYNC or SYNC) gets from msync,
>> - * there is not so much thing to do for CPUs without cache alias,
>> - * But for some CPUs with cache alias, msync has to flush cache
>> - * explicitly, which makes sure the data coherency between memory
>> - * file and cache.
>> - */
>> - file = vma->vm_file;
>> - if (file&& (file->f_op ==&shmem_file_operations)) {
>> - if(CPU_HAS_CACHE_ALIAS)
>> - flush_cache_range(vma, start, start+len);
>> - error = 0;
>> - goto out_unlock;
>> - }
>> -#endif
>> -
>> for (;;) {
>>
>> /* Still start< end. */
>> @@ -97,6 +80,19 @@ SYSCALL_DEFINE3(msync, unsigned long, start,
>> size_t, len, int, flags)
>> goto out_unlock;
>> }
>> file = vma->vm_file;
>> +#ifdef CONFIG_TMPFS
>> + /*
>> + * For tmpfs, no matter which flag(ASYNC or SYNC) gets from msync,
>> + * there is not so much thing to do for CPUs without cache alias,
>> + * But for some CPUs with cache alias, msync has to flush cache
>> + * explicitly, which makes sure the data coherency between memory
>> + * file and cache.
>> + */
>> + if (file&& (file->f_op ==&shmem_file_operations)) {
>> + if(CPU_HAS_CACHE_ALIAS)
>> + flush_cache_range(vma, start, start+len);
>> + }
>> +#endif
>> start = vma->vm_end;
>> if ((flags& MS_SYNC)&& file&&
>> (vma->vm_flags& VM_SHARED)) {
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] mm/msync: tweak tmpfs patch for syscall msync
2012-04-26 0:59 ` Zumeng Chen
@ 2012-04-26 1:15 ` Bruce Ashfield
2012-04-26 1:16 ` Zumeng Chen
0 siblings, 1 reply; 6+ messages in thread
From: Bruce Ashfield @ 2012-04-26 1:15 UTC (permalink / raw)
To: Zumeng Chen; +Cc: yocto
On 12-04-25 8:59 PM, Zumeng Chen wrote:
> That was my last version, you can google to get by "msync zumeng"
> So feel free to merge it.
Sounds good, but we should still get the header updates, since the
first version merged into the tree already.
Bruce
>
> Regards,
> Zumeng
> 于 2012年04月25日 21:47, Bruce Ashfield 写道:
>> On 12-04-25 06:06 AM, Kang Kai wrote:
>>> Commit 1c3ae5441 fixes MIPS CPU cache alias problem. But it makes
>>
>> Put a short log after the commit ID, that way we can read what the
>> old commit was trying to do right in this commit.
>>
>>> posix test cases mlockall/3-6 3-7 fail.
>>
>> Can we expand on what the test is doing ? That way the commit
>> header is stand alone. I know that I haven't memorized what all the
>> posix tests do :)
>>
>>> Tweak the patch to:
>>> 1 check the vma and its flags first
>>
>> Can you expand here as well. Do you really mean that you've moved
>> the CONFIG_TMPFS block down in the function so that the normal
>> vma flag checking will occur ?
>>
>>> 2 don't quit the function when meet first vma belongs to tmpfs file
>>
>> And for this part, can you (or Zumeng) explain why we used to need
>> to exit immediately and now we don't ?
>>
>> The patch looks good though, thanks for looking into this tricky
>> area of code.
>>
>> Cheers,
>>
>> Bruce
>>
>>>
>>> Signed-off-by: Kang Kai<kai.kang@windriver.com>
>>> ---
>>> mm/msync.c | 30 +++++++++++++-----------------
>>> 1 files changed, 13 insertions(+), 17 deletions(-)
>>>
>>> diff --git a/mm/msync.c b/mm/msync.c
>>> index ced6215..31cd311 100644
>>> --- a/mm/msync.c
>>> +++ b/mm/msync.c
>>> @@ -60,23 +60,6 @@ SYSCALL_DEFINE3(msync, unsigned long, start,
>>> size_t, len, int, flags)
>>> down_read(&mm->mmap_sem);
>>> vma = find_vma(mm, start);
>>>
>>> -#ifdef CONFIG_TMPFS
>>> - /*
>>> - * For tmpfs, no matter which flag(ASYNC or SYNC) gets from msync,
>>> - * there is not so much thing to do for CPUs without cache alias,
>>> - * But for some CPUs with cache alias, msync has to flush cache
>>> - * explicitly, which makes sure the data coherency between memory
>>> - * file and cache.
>>> - */
>>> - file = vma->vm_file;
>>> - if (file&& (file->f_op ==&shmem_file_operations)) {
>>> - if(CPU_HAS_CACHE_ALIAS)
>>> - flush_cache_range(vma, start, start+len);
>>> - error = 0;
>>> - goto out_unlock;
>>> - }
>>> -#endif
>>> -
>>> for (;;) {
>>>
>>> /* Still start< end. */
>>> @@ -97,6 +80,19 @@ SYSCALL_DEFINE3(msync, unsigned long, start,
>>> size_t, len, int, flags)
>>> goto out_unlock;
>>> }
>>> file = vma->vm_file;
>>> +#ifdef CONFIG_TMPFS
>>> + /*
>>> + * For tmpfs, no matter which flag(ASYNC or SYNC) gets from msync,
>>> + * there is not so much thing to do for CPUs without cache alias,
>>> + * But for some CPUs with cache alias, msync has to flush cache
>>> + * explicitly, which makes sure the data coherency between memory
>>> + * file and cache.
>>> + */
>>> + if (file&& (file->f_op ==&shmem_file_operations)) {
>>> + if(CPU_HAS_CACHE_ALIAS)
>>> + flush_cache_range(vma, start, start+len);
>>> + }
>>> +#endif
>>> start = vma->vm_end;
>>> if ((flags& MS_SYNC)&& file&&
>>> (vma->vm_flags& VM_SHARED)) {
>>
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] mm/msync: tweak tmpfs patch for syscall msync
2012-04-26 1:15 ` Bruce Ashfield
@ 2012-04-26 1:16 ` Zumeng Chen
2012-04-26 2:00 ` Kang Kai
0 siblings, 1 reply; 6+ messages in thread
From: Zumeng Chen @ 2012-04-26 1:16 UTC (permalink / raw)
To: Bruce Ashfield; +Cc: yocto
于 2012年04月26日 09:15, Bruce Ashfield 写道:
> On 12-04-25 8:59 PM, Zumeng Chen wrote:
>> That was my last version, you can google to get by "msync zumeng"
>> So feel free to merge it.
>
> Sounds good, but we should still get the header updates, since the
> first version merged into the tree already.
Yes, NP, I'm OK with all changes. :)
Regards,
Zumeng
>
> Bruce
>
>>
>> Regards,
>> Zumeng
>> 于 2012年04月25日 21:47, Bruce Ashfield 写道:
>>> On 12-04-25 06:06 AM, Kang Kai wrote:
>>>> Commit 1c3ae5441 fixes MIPS CPU cache alias problem. But it makes
>>>
>>> Put a short log after the commit ID, that way we can read what the
>>> old commit was trying to do right in this commit.
>>>
>>>> posix test cases mlockall/3-6 3-7 fail.
>>>
>>> Can we expand on what the test is doing ? That way the commit
>>> header is stand alone. I know that I haven't memorized what all the
>>> posix tests do :)
>>>
>>>> Tweak the patch to:
>>>> 1 check the vma and its flags first
>>>
>>> Can you expand here as well. Do you really mean that you've moved
>>> the CONFIG_TMPFS block down in the function so that the normal
>>> vma flag checking will occur ?
>>>
>>>> 2 don't quit the function when meet first vma belongs to tmpfs file
>>>
>>> And for this part, can you (or Zumeng) explain why we used to need
>>> to exit immediately and now we don't ?
>>>
>>> The patch looks good though, thanks for looking into this tricky
>>> area of code.
>>>
>>> Cheers,
>>>
>>> Bruce
>>>
>>>>
>>>> Signed-off-by: Kang Kai<kai.kang@windriver.com>
>>>> ---
>>>> mm/msync.c | 30 +++++++++++++-----------------
>>>> 1 files changed, 13 insertions(+), 17 deletions(-)
>>>>
>>>> diff --git a/mm/msync.c b/mm/msync.c
>>>> index ced6215..31cd311 100644
>>>> --- a/mm/msync.c
>>>> +++ b/mm/msync.c
>>>> @@ -60,23 +60,6 @@ SYSCALL_DEFINE3(msync, unsigned long, start,
>>>> size_t, len, int, flags)
>>>> down_read(&mm->mmap_sem);
>>>> vma = find_vma(mm, start);
>>>>
>>>> -#ifdef CONFIG_TMPFS
>>>> - /*
>>>> - * For tmpfs, no matter which flag(ASYNC or SYNC) gets from msync,
>>>> - * there is not so much thing to do for CPUs without cache alias,
>>>> - * But for some CPUs with cache alias, msync has to flush cache
>>>> - * explicitly, which makes sure the data coherency between memory
>>>> - * file and cache.
>>>> - */
>>>> - file = vma->vm_file;
>>>> - if (file&& (file->f_op ==&shmem_file_operations)) {
>>>> - if(CPU_HAS_CACHE_ALIAS)
>>>> - flush_cache_range(vma, start, start+len);
>>>> - error = 0;
>>>> - goto out_unlock;
>>>> - }
>>>> -#endif
>>>> -
>>>> for (;;) {
>>>>
>>>> /* Still start< end. */
>>>> @@ -97,6 +80,19 @@ SYSCALL_DEFINE3(msync, unsigned long, start,
>>>> size_t, len, int, flags)
>>>> goto out_unlock;
>>>> }
>>>> file = vma->vm_file;
>>>> +#ifdef CONFIG_TMPFS
>>>> + /*
>>>> + * For tmpfs, no matter which flag(ASYNC or SYNC) gets from msync,
>>>> + * there is not so much thing to do for CPUs without cache alias,
>>>> + * But for some CPUs with cache alias, msync has to flush cache
>>>> + * explicitly, which makes sure the data coherency between memory
>>>> + * file and cache.
>>>> + */
>>>> + if (file&& (file->f_op ==&shmem_file_operations)) {
>>>> + if(CPU_HAS_CACHE_ALIAS)
>>>> + flush_cache_range(vma, start, start+len);
>>>> + }
>>>> +#endif
>>>> start = vma->vm_end;
>>>> if ((flags& MS_SYNC)&& file&&
>>>> (vma->vm_flags& VM_SHARED)) {
>>>
>>
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] mm/msync: tweak tmpfs patch for syscall msync
2012-04-26 1:16 ` Zumeng Chen
@ 2012-04-26 2:00 ` Kang Kai
0 siblings, 0 replies; 6+ messages in thread
From: Kang Kai @ 2012-04-26 2:00 UTC (permalink / raw)
To: Zumeng Chen; +Cc: yocto
On 2012年04月26日 09:16, Zumeng Chen wrote:
> 于 2012年04月26日 09:15, Bruce Ashfield 写道:
>> On 12-04-25 8:59 PM, Zumeng Chen wrote:
>>> That was my last version, you can google to get by "msync zumeng"
>>> So feel free to merge it.
>>
>> Sounds good, but we should still get the header updates, since the
>> first version merged into the tree already.
> Yes, NP, I'm OK with all changes. :)
Thanks.
I'll send version 2 with header updates.
>
> Regards,
> Zumeng
>>
>> Bruce
>>
>>>
>>> Regards,
>>> Zumeng
>>> 于 2012年04月25日 21:47, Bruce Ashfield 写道:
>>>> On 12-04-25 06:06 AM, Kang Kai wrote:
>>>>> Commit 1c3ae5441 fixes MIPS CPU cache alias problem. But it makes
>>>>
>>>> Put a short log after the commit ID, that way we can read what the
>>>> old commit was trying to do right in this commit.
>>>>
>>>>> posix test cases mlockall/3-6 3-7 fail.
>>>>
>>>> Can we expand on what the test is doing ? That way the commit
>>>> header is stand alone. I know that I haven't memorized what all the
>>>> posix tests do :)
>>>>
>>>>> Tweak the patch to:
>>>>> 1 check the vma and its flags first
>>>>
>>>> Can you expand here as well. Do you really mean that you've moved
>>>> the CONFIG_TMPFS block down in the function so that the normal
>>>> vma flag checking will occur ?
>>>>
>>>>> 2 don't quit the function when meet first vma belongs to tmpfs file
>>>>
>>>> And for this part, can you (or Zumeng) explain why we used to need
>>>> to exit immediately and now we don't ?
>>>>
>>>> The patch looks good though, thanks for looking into this tricky
>>>> area of code.
>>>>
>>>> Cheers,
>>>>
>>>> Bruce
>>>>
>>>>>
>>>>> Signed-off-by: Kang Kai<kai.kang@windriver.com>
>>>>> ---
>>>>> mm/msync.c | 30 +++++++++++++-----------------
>>>>> 1 files changed, 13 insertions(+), 17 deletions(-)
>>>>>
>>>>> diff --git a/mm/msync.c b/mm/msync.c
>>>>> index ced6215..31cd311 100644
>>>>> --- a/mm/msync.c
>>>>> +++ b/mm/msync.c
>>>>> @@ -60,23 +60,6 @@ SYSCALL_DEFINE3(msync, unsigned long, start,
>>>>> size_t, len, int, flags)
>>>>> down_read(&mm->mmap_sem);
>>>>> vma = find_vma(mm, start);
>>>>>
>>>>> -#ifdef CONFIG_TMPFS
>>>>> - /*
>>>>> - * For tmpfs, no matter which flag(ASYNC or SYNC) gets from msync,
>>>>> - * there is not so much thing to do for CPUs without cache alias,
>>>>> - * But for some CPUs with cache alias, msync has to flush cache
>>>>> - * explicitly, which makes sure the data coherency between memory
>>>>> - * file and cache.
>>>>> - */
>>>>> - file = vma->vm_file;
>>>>> - if (file&& (file->f_op ==&shmem_file_operations)) {
>>>>> - if(CPU_HAS_CACHE_ALIAS)
>>>>> - flush_cache_range(vma, start, start+len);
>>>>> - error = 0;
>>>>> - goto out_unlock;
>>>>> - }
>>>>> -#endif
>>>>> -
>>>>> for (;;) {
>>>>>
>>>>> /* Still start< end. */
>>>>> @@ -97,6 +80,19 @@ SYSCALL_DEFINE3(msync, unsigned long, start,
>>>>> size_t, len, int, flags)
>>>>> goto out_unlock;
>>>>> }
>>>>> file = vma->vm_file;
>>>>> +#ifdef CONFIG_TMPFS
>>>>> + /*
>>>>> + * For tmpfs, no matter which flag(ASYNC or SYNC) gets from msync,
>>>>> + * there is not so much thing to do for CPUs without cache alias,
>>>>> + * But for some CPUs with cache alias, msync has to flush cache
>>>>> + * explicitly, which makes sure the data coherency between memory
>>>>> + * file and cache.
>>>>> + */
>>>>> + if (file&& (file->f_op ==&shmem_file_operations)) {
>>>>> + if(CPU_HAS_CACHE_ALIAS)
>>>>> + flush_cache_range(vma, start, start+len);
>>>>> + }
>>>>> +#endif
>>>>> start = vma->vm_end;
>>>>> if ((flags& MS_SYNC)&& file&&
>>>>> (vma->vm_flags& VM_SHARED)) {
>>>>
>>>
>>
>
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2012-04-26 2:00 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-04-25 10:06 [PATCH] mm/msync: tweak tmpfs patch for syscall msync Kang Kai
2012-04-25 13:47 ` Bruce Ashfield
2012-04-26 0:59 ` Zumeng Chen
2012-04-26 1:15 ` Bruce Ashfield
2012-04-26 1:16 ` Zumeng Chen
2012-04-26 2:00 ` Kang Kai
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