| Message ID | 20240311164638.2015063-5-pasha.tatashin@soleen.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Dynamic Kernel Stacks | expand |
Le 11/03/2024 à 17:46, Pasha Tatashin a écrit : > In many places number of pages in the stack is detremined via > (THREAD_SIZE / PAGE_SIZE). There is also a BUG_ON() that ensures that > (THREAD_SIZE / PAGE_SIZE) is indeed equals to vm_area->nr_pages. > > However, with dynamic stacks, the number of pages in vm_area will grow > with stack, therefore, use vm_area->nr_pages to determine the actual > number of pages allocated in stack. > > Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> > --- > kernel/fork.c | 18 +++++++++--------- > 1 file changed, 9 insertions(+), 9 deletions(-) > > diff --git a/kernel/fork.c b/kernel/fork.c > index 60e812825a7a..a35f4008afa0 100644 > --- a/kernel/fork.c > +++ b/kernel/fork.c > @@ -243,13 +243,11 @@ static int free_vm_stack_cache(unsigned int cpu) > > static int memcg_charge_kernel_stack(struct vm_struct *vm) Maybe s/vm/vm_area/ as done in 03/14? CJ > { > - int i; > - int ret; > + int i, ret, nr_pages; > int nr_charged = 0; > > - BUG_ON(vm->nr_pages != THREAD_SIZE / PAGE_SIZE); > - > - for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++) { > + nr_pages = vm->nr_pages; > + for (i = 0; i < nr_pages; i++) { > ret = memcg_kmem_charge_page(vm->pages[i], GFP_KERNEL, 0); > if (ret) > goto err; > @@ -531,9 +529,10 @@ static void account_kernel_stack(struct task_struct *tsk, int account) > { > if (IS_ENABLED(CONFIG_VMAP_STACK)) { > struct vm_struct *vm = task_stack_vm_area(tsk); > - int i; > + int i, nr_pages; > > - for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++) > + nr_pages = vm->nr_pages; > + for (i = 0; i < nr_pages; i++) > mod_lruvec_page_state(vm->pages[i], NR_KERNEL_STACK_KB, > account * (PAGE_SIZE / 1024)); > } else { > @@ -551,10 +550,11 @@ void exit_task_stack_account(struct task_struct *tsk) > > if (IS_ENABLED(CONFIG_VMAP_STACK)) { > struct vm_struct *vm; > - int i; > + int i, nr_pages; > > vm = task_stack_vm_area(tsk); > - for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++) > + nr_pages = vm->nr_pages; > + for (i = 0; i < nr_pages; i++) > memcg_kmem_uncharge_page(vm->pages[i], 0); > } > }
On Sun, Mar 17, 2024 at 10:45 AM Christophe JAILLET <christophe.jaillet@wanadoo.fr> wrote: > > Le 11/03/2024 à 17:46, Pasha Tatashin a écrit : > > In many places number of pages in the stack is detremined via > > (THREAD_SIZE / PAGE_SIZE). There is also a BUG_ON() that ensures that > > (THREAD_SIZE / PAGE_SIZE) is indeed equals to vm_area->nr_pages. > > > > However, with dynamic stacks, the number of pages in vm_area will grow > > with stack, therefore, use vm_area->nr_pages to determine the actual > > number of pages allocated in stack. > > > > Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> > > --- > > kernel/fork.c | 18 +++++++++--------- > > 1 file changed, 9 insertions(+), 9 deletions(-) > > > > diff --git a/kernel/fork.c b/kernel/fork.c > > index 60e812825a7a..a35f4008afa0 100644 > > --- a/kernel/fork.c > > +++ b/kernel/fork.c > > @@ -243,13 +243,11 @@ static int free_vm_stack_cache(unsigned int cpu) > > > > static int memcg_charge_kernel_stack(struct vm_struct *vm) > > Maybe s/vm/vm_area/ as done in 03/14? Yes, I will add it to 03/14. Thank you, Pasha > > CJ > > > { > > - int i; > > - int ret; > > + int i, ret, nr_pages; > > int nr_charged = 0; > > > > - BUG_ON(vm->nr_pages != THREAD_SIZE / PAGE_SIZE); > > - > > - for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++) { > > + nr_pages = vm->nr_pages; > > + for (i = 0; i < nr_pages; i++) { > > ret = memcg_kmem_charge_page(vm->pages[i], GFP_KERNEL, 0); > > if (ret) > > goto err; > > @@ -531,9 +529,10 @@ static void account_kernel_stack(struct task_struct *tsk, int account) > > { > > if (IS_ENABLED(CONFIG_VMAP_STACK)) { > > struct vm_struct *vm = task_stack_vm_area(tsk); > > - int i; > > + int i, nr_pages; > > > > - for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++) > > + nr_pages = vm->nr_pages; > > + for (i = 0; i < nr_pages; i++) > > mod_lruvec_page_state(vm->pages[i], NR_KERNEL_STACK_KB, > > account * (PAGE_SIZE / 1024)); > > } else { > > @@ -551,10 +550,11 @@ void exit_task_stack_account(struct task_struct *tsk) > > > > if (IS_ENABLED(CONFIG_VMAP_STACK)) { > > struct vm_struct *vm; > > - int i; > > + int i, nr_pages; > > > > vm = task_stack_vm_area(tsk); > > - for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++) > > + nr_pages = vm->nr_pages; > > + for (i = 0; i < nr_pages; i++) > > memcg_kmem_uncharge_page(vm->pages[i], 0); > > } > > } >
diff --git a/kernel/fork.c b/kernel/fork.c index 60e812825a7a..a35f4008afa0 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -243,13 +243,11 @@ static int free_vm_stack_cache(unsigned int cpu) static int memcg_charge_kernel_stack(struct vm_struct *vm) { - int i; - int ret; + int i, ret, nr_pages; int nr_charged = 0; - BUG_ON(vm->nr_pages != THREAD_SIZE / PAGE_SIZE); - - for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++) { + nr_pages = vm->nr_pages; + for (i = 0; i < nr_pages; i++) { ret = memcg_kmem_charge_page(vm->pages[i], GFP_KERNEL, 0); if (ret) goto err; @@ -531,9 +529,10 @@ static void account_kernel_stack(struct task_struct *tsk, int account) { if (IS_ENABLED(CONFIG_VMAP_STACK)) { struct vm_struct *vm = task_stack_vm_area(tsk); - int i; + int i, nr_pages; - for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++) + nr_pages = vm->nr_pages; + for (i = 0; i < nr_pages; i++) mod_lruvec_page_state(vm->pages[i], NR_KERNEL_STACK_KB, account * (PAGE_SIZE / 1024)); } else { @@ -551,10 +550,11 @@ void exit_task_stack_account(struct task_struct *tsk) if (IS_ENABLED(CONFIG_VMAP_STACK)) { struct vm_struct *vm; - int i; + int i, nr_pages; vm = task_stack_vm_area(tsk); - for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++) + nr_pages = vm->nr_pages; + for (i = 0; i < nr_pages; i++) memcg_kmem_uncharge_page(vm->pages[i], 0); } }
In many places number of pages in the stack is detremined via (THREAD_SIZE / PAGE_SIZE). There is also a BUG_ON() that ensures that (THREAD_SIZE / PAGE_SIZE) is indeed equals to vm_area->nr_pages. However, with dynamic stacks, the number of pages in vm_area will grow with stack, therefore, use vm_area->nr_pages to determine the actual number of pages allocated in stack. Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> --- kernel/fork.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-)