* [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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