| Message ID | alpine.DEB.2.21.2003061422070.7412@chino.kir.corp.google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/2] mm, shmem: add vmstat for hugepage fallback | expand |
On Fri, Mar 6, 2020 at 2:22 PM David Rientjes <rientjes@google.com> wrote: > > The thp_fault_fallback and thp_file_fallback vmstats are incremented if > either the hugepage allocation fails through the page allocator or the > hugepage charge fails through mem cgroup. > > This patch leaves this field untouched but adds two new fields, > thp_{fault,file}_fallback_charge, which is incremented only when the mem > cgroup charge fails. > > This distinguishes between attempted hugepage allocations that fail due to > fragmentation (or low memory conditions) and those that fail due to mem > cgroup limits. That can be used to determine the impact of fragmentation > on the system by excluding faults that failed due to memcg usage. Yes, it makes sense to me. Reviewed-by: Yang Shi <yang.shi@linux.alibaba.com> > > Signed-off-by: David Rientjes <rientjes@google.com> > --- > Documentation/admin-guide/mm/transhuge.rst | 10 ++++++++++ > include/linux/vm_event_item.h | 3 +++ > mm/huge_memory.c | 2 ++ > mm/shmem.c | 4 +++- > mm/vmstat.c | 2 ++ > 5 files changed, 20 insertions(+), 1 deletion(-) > > diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst > --- a/Documentation/admin-guide/mm/transhuge.rst > +++ b/Documentation/admin-guide/mm/transhuge.rst > @@ -310,6 +310,11 @@ thp_fault_fallback > is incremented if a page fault fails to allocate > a huge page and instead falls back to using small pages. > > +thp_fault_fallback_charge > + is incremented if a page fault fails to charge a huge page and > + instead falls back to using small pages even though the > + allocation was successful. > + > thp_collapse_alloc_failed > is incremented if khugepaged found a range > of pages that should be collapsed into one huge page but failed > @@ -323,6 +328,11 @@ thp_file_fallback > is incremented if a file huge page is attempted to be allocated > but fails and instead falls back to using small pages. > > +thp_file_fallback_charge > + is incremented if a file huge page cannot be charged and instead > + falls back to using small pages even though the allocation was > + successful. > + > thp_file_mapped > is incremented every time a file huge page is mapped into > user address space. > diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h > --- a/include/linux/vm_event_item.h > +++ b/include/linux/vm_event_item.h > @@ -73,10 +73,12 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, > #ifdef CONFIG_TRANSPARENT_HUGEPAGE > THP_FAULT_ALLOC, > THP_FAULT_FALLBACK, > + THP_FAULT_FALLBACK_CHARGE, > THP_COLLAPSE_ALLOC, > THP_COLLAPSE_ALLOC_FAILED, > THP_FILE_ALLOC, > THP_FILE_FALLBACK, > + THP_FILE_FALLBACK_CHARGE, > THP_FILE_MAPPED, > THP_SPLIT_PAGE, > THP_SPLIT_PAGE_FAILED, > @@ -117,6 +119,7 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, > #ifndef CONFIG_TRANSPARENT_HUGEPAGE > #define THP_FILE_ALLOC ({ BUILD_BUG(); 0; }) > #define THP_FILE_FALLBACK ({ BUILD_BUG(); 0; }) > +#define THP_FILE_FALLBACK_CHARGE ({ BUILD_BUG(); 0; }) > #define THP_FILE_MAPPED ({ BUILD_BUG(); 0; }) > #endif > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -597,6 +597,7 @@ static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf, > if (mem_cgroup_try_charge_delay(page, vma->vm_mm, gfp, &memcg, true)) { > put_page(page); > count_vm_event(THP_FAULT_FALLBACK); > + count_vm_event(THP_FAULT_FALLBACK_CHARGE); > return VM_FAULT_FALLBACK; > } > > @@ -1406,6 +1407,7 @@ vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd) > put_page(page); > ret |= VM_FAULT_FALLBACK; > count_vm_event(THP_FAULT_FALLBACK); > + count_vm_event(THP_FAULT_FALLBACK_CHARGE); > goto out; > } > > diff --git a/mm/shmem.c b/mm/shmem.c > --- a/mm/shmem.c > +++ b/mm/shmem.c > @@ -1871,8 +1871,10 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, > error = mem_cgroup_try_charge_delay(page, charge_mm, gfp, &memcg, > PageTransHuge(page)); > if (error) { > - if (PageTransHuge(page)) > + if (PageTransHuge(page)) { > count_vm_event(THP_FILE_FALLBACK); > + count_vm_event(THP_FILE_FALLBACK_CHARGE); > + } > goto unacct; > } > error = shmem_add_to_page_cache(page, mapping, hindex, > diff --git a/mm/vmstat.c b/mm/vmstat.c > --- a/mm/vmstat.c > +++ b/mm/vmstat.c > @@ -1254,10 +1254,12 @@ const char * const vmstat_text[] = { > #ifdef CONFIG_TRANSPARENT_HUGEPAGE > "thp_fault_alloc", > "thp_fault_fallback", > + "thp_fault_fallback_charge", > "thp_collapse_alloc", > "thp_collapse_alloc_failed", > "thp_file_alloc", > "thp_file_fallback", > + "thp_file_fallback_charge", > "thp_file_mapped", > "thp_split_page", > "thp_split_page_failed",
On Fri, Mar 06, 2020 at 02:22:35PM -0800, David Rientjes wrote: > The thp_fault_fallback and thp_file_fallback vmstats are incremented if > either the hugepage allocation fails through the page allocator or the > hugepage charge fails through mem cgroup. > > This patch leaves this field untouched but adds two new fields, > thp_{fault,file}_fallback_charge, which is incremented only when the mem > cgroup charge fails. > > This distinguishes between attempted hugepage allocations that fail due to > fragmentation (or low memory conditions) and those that fail due to mem > cgroup limits. That can be used to determine the impact of fragmentation > on the system by excluding faults that failed due to memcg usage. > > Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > --- > Documentation/admin-guide/mm/transhuge.rst | 10 ++++++++++ > include/linux/vm_event_item.h | 3 +++ > mm/huge_memory.c | 2 ++ > mm/shmem.c | 4 +++- > mm/vmstat.c | 2 ++ > 5 files changed, 20 insertions(+), 1 deletion(-) > > diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst > --- a/Documentation/admin-guide/mm/transhuge.rst > +++ b/Documentation/admin-guide/mm/transhuge.rst > @@ -310,6 +310,11 @@ thp_fault_fallback > is incremented if a page fault fails to allocate > a huge page and instead falls back to using small pages. > > +thp_fault_fallback_charge > + is incremented if a page fault fails to charge a huge page and > + instead falls back to using small pages even though the > + allocation was successful. > + > thp_collapse_alloc_failed > is incremented if khugepaged found a range > of pages that should be collapsed into one huge page but failed > @@ -323,6 +328,11 @@ thp_file_fallback > is incremented if a file huge page is attempted to be allocated > but fails and instead falls back to using small pages. > > +thp_file_fallback_charge > + is incremented if a file huge page cannot be charged and instead > + falls back to using small pages even though the allocation was > + successful. > + > thp_file_mapped > is incremented every time a file huge page is mapped into > user address space. > diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h > --- a/include/linux/vm_event_item.h > +++ b/include/linux/vm_event_item.h > @@ -73,10 +73,12 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, > #ifdef CONFIG_TRANSPARENT_HUGEPAGE > THP_FAULT_ALLOC, > THP_FAULT_FALLBACK, > + THP_FAULT_FALLBACK_CHARGE, > THP_COLLAPSE_ALLOC, > THP_COLLAPSE_ALLOC_FAILED, > THP_FILE_ALLOC, > THP_FILE_FALLBACK, > + THP_FILE_FALLBACK_CHARGE, > THP_FILE_MAPPED, > THP_SPLIT_PAGE, > THP_SPLIT_PAGE_FAILED, > @@ -117,6 +119,7 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, > #ifndef CONFIG_TRANSPARENT_HUGEPAGE > #define THP_FILE_ALLOC ({ BUILD_BUG(); 0; }) > #define THP_FILE_FALLBACK ({ BUILD_BUG(); 0; }) > +#define THP_FILE_FALLBACK_CHARGE ({ BUILD_BUG(); 0; }) > #define THP_FILE_MAPPED ({ BUILD_BUG(); 0; }) > #endif > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -597,6 +597,7 @@ static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf, > if (mem_cgroup_try_charge_delay(page, vma->vm_mm, gfp, &memcg, true)) { > put_page(page); > count_vm_event(THP_FAULT_FALLBACK); > + count_vm_event(THP_FAULT_FALLBACK_CHARGE); > return VM_FAULT_FALLBACK; > } > > @@ -1406,6 +1407,7 @@ vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd) > put_page(page); > ret |= VM_FAULT_FALLBACK; > count_vm_event(THP_FAULT_FALLBACK); > + count_vm_event(THP_FAULT_FALLBACK_CHARGE); > goto out; > } > > diff --git a/mm/shmem.c b/mm/shmem.c > --- a/mm/shmem.c > +++ b/mm/shmem.c > @@ -1871,8 +1871,10 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, > error = mem_cgroup_try_charge_delay(page, charge_mm, gfp, &memcg, > PageTransHuge(page)); > if (error) { > - if (PageTransHuge(page)) > + if (PageTransHuge(page)) { > count_vm_event(THP_FILE_FALLBACK); > + count_vm_event(THP_FILE_FALLBACK_CHARGE); > + } > goto unacct; > } > error = shmem_add_to_page_cache(page, mapping, hindex, > diff --git a/mm/vmstat.c b/mm/vmstat.c > --- a/mm/vmstat.c > +++ b/mm/vmstat.c > @@ -1254,10 +1254,12 @@ const char * const vmstat_text[] = { > #ifdef CONFIG_TRANSPARENT_HUGEPAGE > "thp_fault_alloc", > "thp_fault_fallback", > + "thp_fault_fallback_charge", > "thp_collapse_alloc", > "thp_collapse_alloc_failed", > "thp_file_alloc", > "thp_file_fallback", > + "thp_file_fallback_charge", > "thp_file_mapped", > "thp_split_page", > "thp_split_page_failed",
diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst --- a/Documentation/admin-guide/mm/transhuge.rst +++ b/Documentation/admin-guide/mm/transhuge.rst @@ -310,6 +310,11 @@ thp_fault_fallback is incremented if a page fault fails to allocate a huge page and instead falls back to using small pages. +thp_fault_fallback_charge + is incremented if a page fault fails to charge a huge page and + instead falls back to using small pages even though the + allocation was successful. + thp_collapse_alloc_failed is incremented if khugepaged found a range of pages that should be collapsed into one huge page but failed @@ -323,6 +328,11 @@ thp_file_fallback is incremented if a file huge page is attempted to be allocated but fails and instead falls back to using small pages. +thp_file_fallback_charge + is incremented if a file huge page cannot be charged and instead + falls back to using small pages even though the allocation was + successful. + thp_file_mapped is incremented every time a file huge page is mapped into user address space. diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h --- a/include/linux/vm_event_item.h +++ b/include/linux/vm_event_item.h @@ -73,10 +73,12 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, #ifdef CONFIG_TRANSPARENT_HUGEPAGE THP_FAULT_ALLOC, THP_FAULT_FALLBACK, + THP_FAULT_FALLBACK_CHARGE, THP_COLLAPSE_ALLOC, THP_COLLAPSE_ALLOC_FAILED, THP_FILE_ALLOC, THP_FILE_FALLBACK, + THP_FILE_FALLBACK_CHARGE, THP_FILE_MAPPED, THP_SPLIT_PAGE, THP_SPLIT_PAGE_FAILED, @@ -117,6 +119,7 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, #ifndef CONFIG_TRANSPARENT_HUGEPAGE #define THP_FILE_ALLOC ({ BUILD_BUG(); 0; }) #define THP_FILE_FALLBACK ({ BUILD_BUG(); 0; }) +#define THP_FILE_FALLBACK_CHARGE ({ BUILD_BUG(); 0; }) #define THP_FILE_MAPPED ({ BUILD_BUG(); 0; }) #endif diff --git a/mm/huge_memory.c b/mm/huge_memory.c --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -597,6 +597,7 @@ static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf, if (mem_cgroup_try_charge_delay(page, vma->vm_mm, gfp, &memcg, true)) { put_page(page); count_vm_event(THP_FAULT_FALLBACK); + count_vm_event(THP_FAULT_FALLBACK_CHARGE); return VM_FAULT_FALLBACK; } @@ -1406,6 +1407,7 @@ vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd) put_page(page); ret |= VM_FAULT_FALLBACK; count_vm_event(THP_FAULT_FALLBACK); + count_vm_event(THP_FAULT_FALLBACK_CHARGE); goto out; } diff --git a/mm/shmem.c b/mm/shmem.c --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1871,8 +1871,10 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, error = mem_cgroup_try_charge_delay(page, charge_mm, gfp, &memcg, PageTransHuge(page)); if (error) { - if (PageTransHuge(page)) + if (PageTransHuge(page)) { count_vm_event(THP_FILE_FALLBACK); + count_vm_event(THP_FILE_FALLBACK_CHARGE); + } goto unacct; } error = shmem_add_to_page_cache(page, mapping, hindex, diff --git a/mm/vmstat.c b/mm/vmstat.c --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -1254,10 +1254,12 @@ const char * const vmstat_text[] = { #ifdef CONFIG_TRANSPARENT_HUGEPAGE "thp_fault_alloc", "thp_fault_fallback", + "thp_fault_fallback_charge", "thp_collapse_alloc", "thp_collapse_alloc_failed", "thp_file_alloc", "thp_file_fallback", + "thp_file_fallback_charge", "thp_file_mapped", "thp_split_page", "thp_split_page_failed",
The thp_fault_fallback and thp_file_fallback vmstats are incremented if either the hugepage allocation fails through the page allocator or the hugepage charge fails through mem cgroup. This patch leaves this field untouched but adds two new fields, thp_{fault,file}_fallback_charge, which is incremented only when the mem cgroup charge fails. This distinguishes between attempted hugepage allocations that fail due to fragmentation (or low memory conditions) and those that fail due to mem cgroup limits. That can be used to determine the impact of fragmentation on the system by excluding faults that failed due to memcg usage. Signed-off-by: David Rientjes <rientjes@google.com> --- Documentation/admin-guide/mm/transhuge.rst | 10 ++++++++++ include/linux/vm_event_item.h | 3 +++ mm/huge_memory.c | 2 ++ mm/shmem.c | 4 +++- mm/vmstat.c | 2 ++ 5 files changed, 20 insertions(+), 1 deletion(-)