Re: [PATCH] kvm: x86 mmu: avoid mmu_page_hash lookup for direct_map-only VM

On Fri, May 8, 2020 at 1:14 PM Sean Christopherson wrote: > > On Fri, May 08, 2020 at 11:24:25AM -0700, Jon Cargille wrote: > > From: Peter Feiner > > > > Optimization for avoiding lookups in mmu_page_hash. When there's a > > single direct root, a shadow page has at

[tip:x86/cpu] x86/cpufeatures: Add EPT_AD feature bit

Commit-ID: 301d328a6f8b53bb86c5ecf72db7bc178bcf1999 Gitweb: https://git.kernel.org/tip/301d328a6f8b53bb86c5ecf72db7bc178bcf1999 Author: Peter Feiner AuthorDate: Wed, 1 Aug 2018 11:06:57 -0700 Committer: Thomas Gleixner CommitDate: Fri, 3 Aug 2018 12:36:23 +0200 x86/cpufeatures: Add

[tip:x86/cpu] x86/cpufeatures: Add EPT_AD feature bit

Commit-ID: 301d328a6f8b53bb86c5ecf72db7bc178bcf1999 Gitweb: https://git.kernel.org/tip/301d328a6f8b53bb86c5ecf72db7bc178bcf1999 Author: Peter Feiner AuthorDate: Wed, 1 Aug 2018 11:06:57 -0700 Committer: Thomas Gleixner CommitDate: Fri, 3 Aug 2018 12:36:23 +0200 x86/cpufeatures: Add

Re: [PATCH] KVM: MMU: speedup update_permission_bitmask

On Tue, Sep 12, 2017 at 12:55 PM, Paolo Bonzini <pbonz...@redhat.com> wrote: > On 12/09/2017 18:48, Peter Feiner wrote: >>>> >>>> Because update_permission_bitmask is actually the top item in the profile >>>> for nested vmexits, this speeds up an L

Re: [PATCH] KVM: MMU: speedup update_permission_bitmask

On Tue, Sep 12, 2017 at 12:55 PM, Paolo Bonzini wrote: > On 12/09/2017 18:48, Peter Feiner wrote: >>>> >>>> Because update_permission_bitmask is actually the top item in the profile >>>> for nested vmexits, this speeds up an L2->L1 vmexit by about t

Re: [PATCH] KVM: MMU: speedup update_permission_bitmask

On Mon, Aug 28, 2017 at 12:42 PM, Jim Mattson wrote: > > Looks okay to me, but I'm hoping Peter will chime in. Sorry, this slipped by. Busy couple of weeks! > > > Reviewed-by: Jim Mattson > > On Thu, Aug 24, 2017 at 8:56 AM, Paolo Bonzini

Re: [PATCH] KVM: MMU: speedup update_permission_bitmask

On Mon, Aug 28, 2017 at 12:42 PM, Jim Mattson wrote: > > Looks okay to me, but I'm hoping Peter will chime in. Sorry, this slipped by. Busy couple of weeks! > > > Reviewed-by: Jim Mattson > > On Thu, Aug 24, 2017 at 8:56 AM, Paolo Bonzini wrote: > > update_permission_bitmask currently does a

[tip:perf/urgent] perf trace: Fix documentation for -i

Commit-ID: 956959f6b7a982b2e789a7a8fa1de437074a5eb9 Gitweb: http://git.kernel.org/tip/956959f6b7a982b2e789a7a8fa1de437074a5eb9 Author: Peter Feiner AuthorDate: Wed, 4 Nov 2015 09:21:46 -0800 Committer: Arnaldo Carvalho de Melo CommitDate: Thu, 5 Nov 2015 12:47:51 -0300 perf trace: Fix

[tip:perf/urgent] perf trace: Fix documentation for -i

Commit-ID: 956959f6b7a982b2e789a7a8fa1de437074a5eb9 Gitweb: http://git.kernel.org/tip/956959f6b7a982b2e789a7a8fa1de437074a5eb9 Author: Peter Feiner <pfei...@google.com> AuthorDate: Wed, 4 Nov 2015 09:21:46 -0800 Committer: Arnaldo Carvalho de Melo <a...@redhat.com> CommitDate

[PATCH] perf trace: fix documentation for -i

in a file versus live). Signed-off-by: Peter Feiner --- tools/perf/Documentation/perf-trace.txt | 1 - 1 file changed, 1 deletion(-) diff --git a/tools/perf/Documentation/perf-trace.txt b/tools/perf/Documentation/perf-trace.txt index 7ea0786..13293de 100644 --- a/tools/perf/Documentation/perf

[PATCH] perf trace: fix documentation for -i

in a file versus live). Signed-off-by: Peter Feiner <pfei...@google.com> --- tools/perf/Documentation/perf-trace.txt | 1 - 1 file changed, 1 deletion(-) diff --git a/tools/perf/Documentation/perf-trace.txt b/tools/perf/Documentation/perf-trace.txt index 7ea0786..13293de 100644 --- a/tool

Re: [PATCH 00/17] RFC: userfault v2

On Fri, Oct 31, 2014 at 11:29:49AM +0800, zhanghailiang wrote: > Agreed, but for doing live memory snapshot (VM is running when do snapsphot), > we have to do this (block the write action), because we have to save the page > before it > is dirtied by writing action. This is the difference,

Re: [PATCH 5/5] mm: gup: kvm use get_user_pages_unlocked

ble to block indefinitely by being allowed to release the mmap_sem). > > Signed-off-by: Andrea Arcangeli Reviewed-by: Peter Feiner -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo inf

Re: [PATCH 2/5] mm: gup: add __get_user_pages_unlocked to customize gup_flags

; > Signed-off-by: Andrea Arcangeli Reviewed-by: Peter Feiner -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/

Re: [PATCH 3/5] mm: gup: use get_user_pages_unlocked within get_user_pages_fast

On Wed, Oct 29, 2014 at 05:35:18PM +0100, Andrea Arcangeli wrote: > This allows the get_user_pages_fast slow path to release the mmap_sem > before blocking. > > Signed-off-by: Andrea Arcangeli Reviewed-by: Peter Feiner -- To unsubscribe from this list: send the line "unsubsc

Re: [PATCH 4/5] mm: gup: use get_user_pages_unlocked

On Wed, Oct 29, 2014 at 05:35:19PM +0100, Andrea Arcangeli wrote: > This allows those get_user_pages calls to pass FAULT_FLAG_ALLOW_RETRY > to the page fault in order to release the mmap_sem during the I/O. > > Signed-off-by: Andrea Arcangeli Reviewed-by: Peter Feiner > diff -

Re: [PATCH 4/5] mm: gup: use get_user_pages_unlocked

On Wed, Oct 29, 2014 at 05:35:19PM +0100, Andrea Arcangeli wrote: This allows those get_user_pages calls to pass FAULT_FLAG_ALLOW_RETRY to the page fault in order to release the mmap_sem during the I/O. Signed-off-by: Andrea Arcangeli aarca...@redhat.com Reviewed-by: Peter Feiner pfei

Re: [PATCH 3/5] mm: gup: use get_user_pages_unlocked within get_user_pages_fast

On Wed, Oct 29, 2014 at 05:35:18PM +0100, Andrea Arcangeli wrote: This allows the get_user_pages_fast slow path to release the mmap_sem before blocking. Signed-off-by: Andrea Arcangeli aarca...@redhat.com Reviewed-by: Peter Feiner pfei...@google.com -- To unsubscribe from this list: send

Re: [PATCH 2/5] mm: gup: add __get_user_pages_unlocked to customize gup_flags

-by: Andrea Arcangeli aarca...@redhat.com Reviewed-by: Peter Feiner pfei...@google.com -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http

Re: [PATCH 5/5] mm: gup: kvm use get_user_pages_unlocked

indefinitely by being allowed to release the mmap_sem). Signed-off-by: Andrea Arcangeli aarca...@redhat.com Reviewed-by: Peter Feiner pfei...@google.com -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info

Re: [PATCH 00/17] RFC: userfault v2

On Fri, Oct 31, 2014 at 11:29:49AM +0800, zhanghailiang wrote: Agreed, but for doing live memory snapshot (VM is running when do snapsphot), we have to do this (block the write action), because we have to save the page before it is dirtied by writing action. This is the difference, compared

Re: [PATCH 00/17] RFC: userfault v2

On Thu, Oct 30, 2014 at 07:31:48PM +0800, zhanghailiang wrote: > On 2014/10/30 1:46, Andrea Arcangeli wrote: > >On Mon, Oct 27, 2014 at 05:32:51PM +0800, zhanghailiang wrote: > >>I want to confirm a question: > >>Can we support distinguishing between writing and reading memory for > >>userfault?

Re: [PATCH 00/17] RFC: userfault v2

On Thu, Oct 30, 2014 at 07:31:48PM +0800, zhanghailiang wrote: On 2014/10/30 1:46, Andrea Arcangeli wrote: On Mon, Oct 27, 2014 at 05:32:51PM +0800, zhanghailiang wrote: I want to confirm a question: Can we support distinguishing between writing and reading memory for userfault? That is, we

Re: [PATCH 10/17] mm: rmap preparation for remap_anon_pages

On Tue, Oct 07, 2014 at 05:52:47PM +0200, Andrea Arcangeli wrote: > I probably grossly overestimated the benefits of resolving the > userfault with a zerocopy page move, sorry. [...] For posterity, I think it's worth noting that most expensive aspect of a TLB shootdown is the interprocessor

Re: [PATCH 10/17] mm: rmap preparation for remap_anon_pages

On Tue, Oct 07, 2014 at 05:52:47PM +0200, Andrea Arcangeli wrote: I probably grossly overestimated the benefits of resolving the userfault with a zerocopy page move, sorry. [...] For posterity, I think it's worth noting that most expensive aspect of a TLB shootdown is the interprocessor

Re: [PATCH v2] mm: softdirty: unmapped addresses between VMAs are clean

On Fri, Sep 26, 2014 at 04:33:26PM -0400, Naoya Horiguchi wrote: > Could you test and merge the following change? Many apologies for the late reply! Your email was in my spam folder :-( I see that Andrew has already merged the patch, so we're in good shape! Thanks for fixing this bug Naoya! --

Re: [PATCH 2/4] mm: gup: add get_user_pages_locked and get_user_pages_unlocked

On Wed, Oct 01, 2014 at 10:56:35AM +0200, Andrea Arcangeli wrote: > +static inline long __get_user_pages_locked(struct task_struct *tsk, > +struct mm_struct *mm, > +unsigned long start, > +

Re: [PATCH 2/4] mm: gup: add get_user_pages_locked and get_user_pages_unlocked

On Wed, Oct 01, 2014 at 10:56:35AM +0200, Andrea Arcangeli wrote: +static inline long __get_user_pages_locked(struct task_struct *tsk, +struct mm_struct *mm, +unsigned long start, +

Re: [PATCH v2] mm: softdirty: unmapped addresses between VMAs are clean

On Fri, Sep 26, 2014 at 04:33:26PM -0400, Naoya Horiguchi wrote: Could you test and merge the following change? Many apologies for the late reply! Your email was in my spam folder :-( I see that Andrew has already merged the patch, so we're in good shape! Thanks for fixing this bug Naoya! -- To

Re: linux-next: manual merge of the akpm-current tree with the pci tree

On Thu, Sep 25, 2014 at 05:47:30PM +1000, Stephen Rothwell wrote: > Hi Andrew, > > Today's linux-next merge of the akpm-current tree got a conflict in > include/asm-generic/pgtable.h between commit b766eafe6828 ("PCI: Add > pci_remap_iospace() to map bus I/O resources") from the pci tree and >

Re: linux-next: manual merge of the akpm-current tree with the pci tree

On Thu, Sep 25, 2014 at 05:47:30PM +1000, Stephen Rothwell wrote: Hi Andrew, Today's linux-next merge of the akpm-current tree got a conflict in include/asm-generic/pgtable.h between commit b766eafe6828 (PCI: Add pci_remap_iospace() to map bus I/O resources) from the pci tree and commit

[PATCH v3 1/3] tools: add .gitignore entries for selftests

/selftests/vm/map_hugetlb tools/testing/selftests/vm/thuge-gen tools/testing/selftests/mount/unprivileged-remount-test in the list of untracked files. Signed-off-by: Peter Feiner --- v1 -> v2: * added changelog blurb * added mount/.gitignore for unprivileged-remount-t

[PATCH v3 2/3] tools: adding clean target to user selftest

Gets rid of this error when running 'make clean' in the selftests directory: make[1]: Entering directory `.../tools/testing/selftests/user' make[1]: *** No rule to make target `clean'. Stop. Signed-off-by: Peter Feiner --- v1 -> v2: Separated this from the parallel build patch.

[PATCH v3 3/3] tools: parallel selftests building & running

Now make -jN builds and runs selftests in parallel. Also, if one selftest fails to build or run, make will return an error, whereas before the error was ignored. Signed-off-by: Peter Feiner --- v1 -> v2: Moved fix for missing 'make clean' target into separate patch. --- to

[PATCH v2 0/3] tools: selftests cleanup

A couple of small patches to make working with selftests easier. v1 -> v2: Addressed Shuah's comments. v2 -> v3: Forgot Signed-off-by footer. *** BLURB HERE *** Peter Feiner (3): tools: add .gitignore entries for selftests tools: adding clean target to user selftest

[PATCH v2 0/3] tools: selftests cleanup

A couple of small patches to make working with selftests easier. v1 - v2: Addressed Shuah's comments. v2 - v3: Forgot Signed-off-by footer. *** BLURB HERE *** Peter Feiner (3): tools: add .gitignore entries for selftests tools: adding clean target to user selftest tools

[PATCH v3 3/3] tools: parallel selftests building running

Now make -jN builds and runs selftests in parallel. Also, if one selftest fails to build or run, make will return an error, whereas before the error was ignored. Signed-off-by: Peter Feiner pfei...@google.com --- v1 - v2: Moved fix for missing 'make clean' target into separate

[PATCH v3 2/3] tools: adding clean target to user selftest

Gets rid of this error when running 'make clean' in the selftests directory: make[1]: Entering directory `.../tools/testing/selftests/user' make[1]: *** No rule to make target `clean'. Stop. Signed-off-by: Peter Feiner pfei...@google.com --- v1 - v2: Separated this from the parallel

[PATCH v3 1/3] tools: add .gitignore entries for selftests

/selftests/vm/map_hugetlb tools/testing/selftests/vm/thuge-gen tools/testing/selftests/mount/unprivileged-remount-test in the list of untracked files. Signed-off-by: Peter Feiner pfei...@google.com --- v1 - v2: * added changelog blurb * added mount/.gitignore

[PATCH v2 2/3] tools: adding clean target to user selftest

Gets rid of this error when running 'make clean' in the selftests directory: make[1]: Entering directory `.../tools/testing/selftests/user' make[1]: *** No rule to make target `clean'. Stop. --- v1 -> v2: Separated this from the parallel build patch. ---

[PATCH v2 1/3] tools: add .gitignore entries for selftests

/selftests/vm/map_hugetlb tools/testing/selftests/vm/thuge-gen tools/testing/selftests/mount/unprivileged-remount-test in the list of untracked files. Signed-off-by: Peter Feiner --- v1 -> v2: * added changelog blurb * added mount/.gitignore for unprivileged-remount-t

[PATCH v2 0/3] tools: selftests cleanup

A couple of small patches to make working with selftests easier. v1 -> v2: Addressed Shuah's comments. Peter Feiner (3): tools: add .gitignore entries for selftests tools: adding clean target to user selftest tools: parallel selftests building & running tools/testing/se

[PATCH v2 3/3] tools: parallel selftests building & running

Now make -jN builds and runs selftests in parallel. Also, if one selftest fails to build or run, make will return an error, whereas before the error was ignored. Signed-off-by: Peter Feiner --- v1 -> v2: Moved fix for missing 'make clean' target into separate patch. --- to

[PATCH 3/3] tools: parallel selftests building & running

Now make -jN builds and runs selftests in parallel. Also, if one selftest fails to build or run, make will return an error, whereas before the error was ignored. Also added missing clean target to user/Makefile so 'make clean' doesn't fail. Signed-off-by: Peter Feiner --- tools/testing

[PATCH 2/3] tools: fix warning in memfd_test

No arguments given after printf format string with "%s" conversion. Signed-off-by: Peter Feiner --- There are a couple of patches floating around for this one. I'm just including it so somebody that applies this patch series doesn't get a broken build :-) --- tools/testing/selft

[PATCH 1/3] tools: add .gitignore entries for selftests

Signed-off-by: Peter Feiner --- tools/testing/selftests/breakpoints/.gitignore | 1 + tools/testing/selftests/efivarfs/.gitignore| 2 ++ tools/testing/selftests/ptrace/.gitignore | 1 + tools/testing/selftests/timers/.gitignore | 1 + tools/testing/selftests/vm/.gitignore

[PATCH 0/3] tools: selftests cleanup

A couple of small patches to make working with selftests easier. Peter Feiner (3): tools: add .gitignore entries for selftests tools: fix warning in memfd_test tools: parallel selftests building & running tools/testing/selftests/Makefile

[PATCH 0/3] tools: selftests cleanup

A couple of small patches to make working with selftests easier. Peter Feiner (3): tools: add .gitignore entries for selftests tools: fix warning in memfd_test tools: parallel selftests building running tools/testing/selftests/Makefile | 49 +++--- tools

[PATCH 1/3] tools: add .gitignore entries for selftests

Signed-off-by: Peter Feiner pfei...@google.com --- tools/testing/selftests/breakpoints/.gitignore | 1 + tools/testing/selftests/efivarfs/.gitignore| 2 ++ tools/testing/selftests/ptrace/.gitignore | 1 + tools/testing/selftests/timers/.gitignore | 1 + tools/testing/selftests/vm

[PATCH 3/3] tools: parallel selftests building running

Now make -jN builds and runs selftests in parallel. Also, if one selftest fails to build or run, make will return an error, whereas before the error was ignored. Also added missing clean target to user/Makefile so 'make clean' doesn't fail. Signed-off-by: Peter Feiner pfei...@google.com

[PATCH 2/3] tools: fix warning in memfd_test

No arguments given after printf format string with %s conversion. Signed-off-by: Peter Feiner pfei...@google.com --- There are a couple of patches floating around for this one. I'm just including it so somebody that applies this patch series doesn't get a broken build :-) --- tools/testing

[PATCH v2 3/3] tools: parallel selftests building running

Now make -jN builds and runs selftests in parallel. Also, if one selftest fails to build or run, make will return an error, whereas before the error was ignored. Signed-off-by: Peter Feiner pfei...@google.com --- v1 - v2: Moved fix for missing 'make clean' target into separate

[PATCH v2 2/3] tools: adding clean target to user selftest

Gets rid of this error when running 'make clean' in the selftests directory: make[1]: Entering directory `.../tools/testing/selftests/user' make[1]: *** No rule to make target `clean'. Stop. --- v1 - v2: Separated this from the parallel build patch. ---

[PATCH v2 0/3] tools: selftests cleanup

A couple of small patches to make working with selftests easier. v1 - v2: Addressed Shuah's comments. Peter Feiner (3): tools: add .gitignore entries for selftests tools: adding clean target to user selftest tools: parallel selftests building running tools/testing/selftests

[PATCH v2 1/3] tools: add .gitignore entries for selftests

/selftests/vm/map_hugetlb tools/testing/selftests/vm/thuge-gen tools/testing/selftests/mount/unprivileged-remount-test in the list of untracked files. Signed-off-by: Peter Feiner pfei...@google.com --- v1 - v2: * added changelog blurb * added mount/.gitignore

[PATCH] mm: softdirty: keep bit when zapping file pte

86/include/asm/pgtable.h with __must_check and rebuilt. Signed-off-by: Peter Feiner --- mm/memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/memory.c b/mm/memory.c index adeac30..fc46934 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1125,7 +1125,

[PATCH] mm: softdirty: keep bit when zapping file pte

/asm/pgtable.h with __must_check and rebuilt. Signed-off-by: Peter Feiner pfei...@google.com --- mm/memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/memory.c b/mm/memory.c index adeac30..fc46934 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1125,7 +1125,7 @@ again

[PATCH v2] mm: softdirty: addresses before VMAs in PTE holes aren't softdirty

but neglected to observe the start of VMAs returned by find_vma. Tested: Wrote a selftest that creates a PMD-sized VMA then unmaps the first page and asserts that the page is not softdirty. I'm going to send the pagemap selftest in a later commit. Signed-off-by: Peter Feiner --- v1 ->

[PATCH v2] mm: softdirty: unmapped addresses between VMAs are clean

the program given above. I'm going to include this code in a selftest in the future. Signed-off-by: Peter Feiner --- v1 -> v2: Restructured patch to make logic more clear. --- fs/proc/task_mmu.c | 61 +++--- 1 file changed, 40 inser

[PATCH v2] mm: softdirty: unmapped addresses between VMAs are clean

to include this code in a selftest in the future. Signed-off-by: Peter Feiner pfei...@google.com --- v1 - v2: Restructured patch to make logic more clear. --- fs/proc/task_mmu.c | 61 +++--- 1 file changed, 40 insertions(+), 21

[PATCH v2] mm: softdirty: addresses before VMAs in PTE holes aren't softdirty

but neglected to observe the start of VMAs returned by find_vma. Tested: Wrote a selftest that creates a PMD-sized VMA then unmaps the first page and asserts that the page is not softdirty. I'm going to send the pagemap selftest in a later commit. Signed-off-by: Peter Feiner pfei...@google.com

Re: [PATCH] mm: softdirty: unmapped addresses between VMAs are clean

On Wed, Sep 10, 2014 at 04:36:28PM -0700, Andrew Morton wrote: > On Wed, 10 Sep 2014 16:24:46 -0700 Peter Feiner wrote: > > @@ -1048,32 +1048,51 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned > > long addr, unsigned long end, > > + while (1) { > > + u

[PATCH] mm: softdirty: unmapped addresses between VMAs are clean

the program given above. I'm going to include this code in a selftest in the future. Signed-off-by: Peter Feiner --- fs/proc/task_mmu.c | 61 +++--- 1 file changed, 40 insertions(+), 21 deletions(-) diff --git a/fs/proc/task_mmu.c b/fs/p

[PATCH] mm: softdirty: addresses before VMAs in PTE holes aren't softdirty

but neglected to observe the start of VMAs returned by find_vma. Tested: Wrote a selftest that creates a PMD-sized VMA then unmaps the first page and asserts that the page is not softdirty. I'm going to send the pagemap selftest in a later commit. Signed-off-by: Peter Feiner --- fs/proc/task_mmu.c

[PATCH] mm: softdirty: addresses before VMAs in PTE holes aren't softdirty

but neglected to observe the start of VMAs returned by find_vma. Tested: Wrote a selftest that creates a PMD-sized VMA then unmaps the first page and asserts that the page is not softdirty. I'm going to send the pagemap selftest in a later commit. Signed-off-by: Peter Feiner pfei...@google.com --- fs

[PATCH] mm: softdirty: unmapped addresses between VMAs are clean

to include this code in a selftest in the future. Signed-off-by: Peter Feiner pfei...@google.com --- fs/proc/task_mmu.c | 61 +++--- 1 file changed, 40 insertions(+), 21 deletions(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index

Re: [PATCH] mm: softdirty: unmapped addresses between VMAs are clean

On Wed, Sep 10, 2014 at 04:36:28PM -0700, Andrew Morton wrote: On Wed, 10 Sep 2014 16:24:46 -0700 Peter Feiner pfei...@google.com wrote: @@ -1048,32 +1048,51 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, + while (1) { + unsigned long

[PATCH v6] mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared

notifications with care, this patch fixes a bug in mprotect where vm_page_prot bits set by drivers were zapped on mprotect. An analogous bug was fixed in mmap by c9d0bf241451a3ab7d02e1652c22b80cd7d93e8f. Reported-by: Peter Feiner Suggested-by: Kirill A. Shutemov Signed-off-by: Peter Feiner --- v1 -

Re: [PATCH v5] mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared

On Thu, Sep 04, 2014 at 09:43:11AM -0700, Peter Feiner wrote: > On Mon, Aug 25, 2014 at 09:45:34PM -0700, Hugh Dickins wrote: > > That sets me wondering: have you placed the VM_SOFTDIRTY check in the > > right place in this series of tests? > > > > I think, once pgprot

Re: [PATCH v5] mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared

On Thu, Sep 04, 2014 at 09:43:11AM -0700, Peter Feiner wrote: On Mon, Aug 25, 2014 at 09:45:34PM -0700, Hugh Dickins wrote: That sets me wondering: have you placed the VM_SOFTDIRTY check in the right place in this series of tests? I think, once pgprot_modify() is correct on all

[PATCH v6] mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared

with care, this patch fixes a bug in mprotect where vm_page_prot bits set by drivers were zapped on mprotect. An analogous bug was fixed in mmap by c9d0bf241451a3ab7d02e1652c22b80cd7d93e8f. Reported-by: Peter Feiner pfei...@google.com Suggested-by: Kirill A. Shutemov kirill.shute...@linux.intel.com Signed

Re: [PATCH v5] mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared

On Mon, Aug 25, 2014 at 09:45:34PM -0700, Hugh Dickins wrote: > On Sun, 24 Aug 2014, Peter Feiner wrote: > > With this patch, write notifications are enabled when VM_SOFTDIRTY is > > cleared. Furthermore, to avoid unnecessary faults, write > > notifications are disabled when

Re: [PATCH v5] mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared

On Mon, Aug 25, 2014 at 09:45:34PM -0700, Hugh Dickins wrote: On Sun, 24 Aug 2014, Peter Feiner wrote: With this patch, write notifications are enabled when VM_SOFTDIRTY is cleared. Furthermore, to avoid unnecessary faults, write notifications are disabled when VM_SOFTDIRTY is reset

[PATCH v5] mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared

notifications with care, this patch fixes a bug in mprotect where vm_page_prot bits set by drivers were zapped on mprotect. An analogous bug was fixed in mmap by c9d0bf241451a3ab7d02e1652c22b80cd7d93e8f. Reported-by: Peter Feiner Suggested-by: Kirill A. Shutemov Reviewed-by: Kirill A. Shute

[PATCH v4] mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared

notifications with care, this patch fixes a bug in mprotect where vm_page_prot bits set by drivers were zapped on mprotect. An analogous bug was fixed in mmap by c9d0bf241451a3ab7d02e1652c22b80cd7d93e8f. Reported-by: Peter Feiner Suggested-by: Kirill A. Shutemov Reviewed-by: Kirill A. Shutemo

[PATCH v4] mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared

with care, this patch fixes a bug in mprotect where vm_page_prot bits set by drivers were zapped on mprotect. An analogous bug was fixed in mmap by c9d0bf241451a3ab7d02e1652c22b80cd7d93e8f. Reported-by: Peter Feiner pfei...@google.com Suggested-by: Kirill A. Shutemov kirill.shute...@linux.intel.com

[PATCH v5] mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared

with care, this patch fixes a bug in mprotect where vm_page_prot bits set by drivers were zapped on mprotect. An analogous bug was fixed in mmap by c9d0bf241451a3ab7d02e1652c22b80cd7d93e8f. Reported-by: Peter Feiner pfei...@google.com Suggested-by: Kirill A. Shutemov kirill.shute...@linux.intel.com

[PATCH v3] mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared

For VMAs that don't want write notifications, PTEs created for read faults have their write bit set. If the read fault happens after VM_SOFTDIRTY is cleared, then the PTE's softdirty bit will remain clear after subsequent writes. Here's a simple code snippet to demonstrate the bug: char* m =

Re: [PATCH v2 1/3] mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared

On Sun, Aug 24, 2014 at 02:50:58AM +0300, Kirill A. Shutemov wrote: > One more case to consider: mprotect() which doesn't trigger successful > vma_merge() will not set VM_SOFTDIRTY and will not enable write-protect on > the vma. > > It's probably better to take VM_SOFTDIRTY into account in >

Re: [PATCH v2 1/3] mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared

On Sun, Aug 24, 2014 at 02:00:11AM +0300, Kirill A. Shutemov wrote: > On Sat, Aug 23, 2014 at 06:11:59PM -0400, Peter Feiner wrote: > > diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c > > index dfc791c..f1a5382 100644 > > --- a/fs/proc/task_mmu.c > > +++ b/fs/pr

[PATCH v2 2/3] mm: mprotect: preserve special page protection bits

We don't want to zap special page protection bits on mprotect. Analogous to the bug fixed in c9d0bf241451a3ab7d02e1652c22b80cd7d93e8f where vm_page_prot bits set by drivers were zapped when write notifications were enabled on new VMAs. Signed-off-by: Peter Feiner --- mm/mprotect.c | 2 +- 1

[PATCH v2 1/3] mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared

should dirty the page */ assert(soft_dirty(x)); /* fails */ With this patch, write notifications are enabled when VM_SOFTDIRTY is cleared. Furthermore, to avoid faults, write notifications are disabled when VM_SOFTDIRTY is reset. Signed-off-by: Peter Feiner --- v1 -> v2: Instead of check

[PATCH v2 3/3] mm: mmap: cleanup code that preserves special vm_page_prot bits

Replace logic that has been factored out into a utility method. Signed-off-by: Peter Feiner --- mm/mmap.c | 16 ++-- 1 file changed, 2 insertions(+), 14 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index abcac32..c18c49a 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1618,20 +1618,8

[PATCH v2 0/3] softdirty fix and write notification cleanup

Here's the new patch that uses Kirill's approach of setting write notifications on the VMA. I also included write notification cleanups and fixes per our discussion. Peter Feiner (3): mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared mm: mprotect: preserve

[PATCH v2 0/3] softdirty fix and write notification cleanup

Here's the new patch that uses Kirill's approach of setting write notifications on the VMA. I also included write notification cleanups and fixes per our discussion. Peter Feiner (3): mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared mm: mprotect: preserve

[PATCH v2 3/3] mm: mmap: cleanup code that preserves special vm_page_prot bits

Replace logic that has been factored out into a utility method. Signed-off-by: Peter Feiner pfei...@google.com --- mm/mmap.c | 16 ++-- 1 file changed, 2 insertions(+), 14 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index abcac32..c18c49a 100644 --- a/mm/mmap.c +++ b/mm/mmap.c

[PATCH v2 1/3] mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared

the page */ assert(soft_dirty(x)); /* fails */ With this patch, write notifications are enabled when VM_SOFTDIRTY is cleared. Furthermore, to avoid faults, write notifications are disabled when VM_SOFTDIRTY is reset. Signed-off-by: Peter Feiner pfei...@google.com --- v1 - v2: Instead of checking

[PATCH v2 2/3] mm: mprotect: preserve special page protection bits

We don't want to zap special page protection bits on mprotect. Analogous to the bug fixed in c9d0bf241451a3ab7d02e1652c22b80cd7d93e8f where vm_page_prot bits set by drivers were zapped when write notifications were enabled on new VMAs. Signed-off-by: Peter Feiner pfei...@google.com --- mm

Re: [PATCH v2 1/3] mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared

On Sun, Aug 24, 2014 at 02:00:11AM +0300, Kirill A. Shutemov wrote: On Sat, Aug 23, 2014 at 06:11:59PM -0400, Peter Feiner wrote: diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index dfc791c..f1a5382 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -851,8 +851,23

Re: [PATCH v2 1/3] mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared

On Sun, Aug 24, 2014 at 02:50:58AM +0300, Kirill A. Shutemov wrote: One more case to consider: mprotect() which doesn't trigger successful vma_merge() will not set VM_SOFTDIRTY and will not enable write-protect on the vma. It's probably better to take VM_SOFTDIRTY into account in

[PATCH v3] mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared

For VMAs that don't want write notifications, PTEs created for read faults have their write bit set. If the read fault happens after VM_SOFTDIRTY is cleared, then the PTE's softdirty bit will remain clear after subsequent writes. Here's a simple code snippet to demonstrate the bug: char* m =

Re: [PATCH] mm: softdirty: write protect PTEs created for read faults after VM_SOFTDIRTY cleared

On Fri, Aug 22, 2014 at 12:51:47AM +0300, Kirill A. Shutemov wrote: > > > One thing: there could be (I haven't checked) complications on > > > vma_merge(): since vm_flags are identical it assumes that it can reuse > > > vma->vm_page_prot of expanded vma. But VM_SOFTDIRTY is excluded from > > >

Re: [PATCH] mm: softdirty: write protect PTEs created for read faults after VM_SOFTDIRTY cleared

On Fri, Aug 22, 2014 at 12:39:42AM +0300, Kirill A. Shutemov wrote: > On Fri, Aug 22, 2014 at 12:51:15AM +0400, Cyrill Gorcunov wrote: > > Looks good to me. > > Would you mind to apply the same pgprot_modify() approach on the > clear_refs_write(), test and post the patch? > > Feel free to use

Re: [PATCH] mm: softdirty: write protect PTEs created for read faults after VM_SOFTDIRTY cleared

On Thu, Aug 21, 2014 at 02:45:43AM +0300, Kirill A. Shutemov wrote: > On Wed, Aug 20, 2014 at 05:46:22PM -0400, Peter Feiner wrote: > It basically means VM_SOFTDIRTY require writenotify on the vma. > > What about patch below? Untested. And it seems it'll introduce bug similar &g

Re: [PATCH] mm: softdirty: write protect PTEs created for read faults after VM_SOFTDIRTY cleared

On Thu, Aug 21, 2014 at 02:45:43AM +0300, Kirill A. Shutemov wrote: On Wed, Aug 20, 2014 at 05:46:22PM -0400, Peter Feiner wrote: It basically means VM_SOFTDIRTY require writenotify on the vma. What about patch below? Untested. And it seems it'll introduce bug similar to bug fixed

Re: [PATCH] mm: softdirty: write protect PTEs created for read faults after VM_SOFTDIRTY cleared

On Fri, Aug 22, 2014 at 12:39:42AM +0300, Kirill A. Shutemov wrote: On Fri, Aug 22, 2014 at 12:51:15AM +0400, Cyrill Gorcunov wrote: Looks good to me. Would you mind to apply the same pgprot_modify() approach on the clear_refs_write(), test and post the patch? Feel free to use my

Re: [PATCH] mm: softdirty: write protect PTEs created for read faults after VM_SOFTDIRTY cleared

On Fri, Aug 22, 2014 at 12:51:47AM +0300, Kirill A. Shutemov wrote: One thing: there could be (I haven't checked) complications on vma_merge(): since vm_flags are identical it assumes that it can reuse vma-vm_page_prot of expanded vma. But VM_SOFTDIRTY is excluded from vm_flags

[PATCH] mm: softdirty: write protect PTEs created for read faults after VM_SOFTDIRTY cleared

irty the page */ assert(soft_dirty(x)); /* fails */ With this patch, new PTEs created for read faults are write protected if the VMA has VM_SOFTDIRTY clear. Signed-off-by: Peter Feiner --- mm/memory.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/memory.c b/mm/memory.c index ab3537b..2

[PATCH] mm: softdirty: write protect PTEs created for read faults after VM_SOFTDIRTY cleared

*/ assert(soft_dirty(x)); /* fails */ With this patch, new PTEs created for read faults are write protected if the VMA has VM_SOFTDIRTY clear. Signed-off-by: Peter Feiner pfei...@google.com --- mm/memory.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/memory.c b/mm/memory.c index ab3537b

Re: [PATCH -mm v6 06/13] pagemap: use walk->vma instead of calling find_vma()

On Fri, Aug 01, 2014 at 03:20:42PM -0400, Naoya Horiguchi wrote: > Page table walker has the information of the current vma in mm_walk, so > we don't have to call find_vma() in each pagemap_hugetlb_range() call. You could also get rid of a bunch of code in pagemap_pte_range: ---

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