From: Pasha Tatashin <pasha.tatashin@soleen.com>
To: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
akpm@linux-foundation.org, x86@kernel.org, bp@alien8.de,
brauner@kernel.org, bristot@redhat.com, bsegall@google.com,
dave.hansen@linux.intel.com, dianders@chromium.org,
dietmar.eggemann@arm.com, eric.devolder@oracle.com,
hca@linux.ibm.com, hch@infradead.org, hpa@zytor.com,
jacob.jun.pan@linux.intel.com, jgg@ziepe.ca,
jpoimboe@kernel.org, jroedel@suse.de, juri.lelli@redhat.com,
kent.overstreet@linux.dev, kinseyho@google.com,
kirill.shutemov@linux.intel.com, lstoakes@gmail.com,
luto@kernel.org, mgorman@suse.de, mic@digikod.net,
michael.christie@oracle.com, mingo@redhat.com,
mjguzik@gmail.com, mst@redhat.com, npiggin@gmail.com,
peterz@infradead.org, pmladek@suse.com,
rick.p.edgecombe@intel.com, rostedt@goodmis.org,
surenb@google.com, tglx@linutronix.de, urezki@gmail.com,
vincent.guittot@linaro.org
Subject: Re: [RFC 03/14] fork: Clean-up naming of vm_strack/vm_struct variables in vmap stacks code
Date: Tue, 19 Mar 2024 12:32:18 -0400 [thread overview]
Message-ID: <CA+CK2bB-7fUnMXcRLma60J-wFZ9Y-W45O0okU2fseuh-VxG8fA@mail.gmail.com> (raw)
In-Reply-To: <1af02bc8-1b20-4508-909d-342f3b06bf78@wanadoo.fr>
On Sun, Mar 17, 2024 at 10:42 AM Christophe JAILLET
<christophe.jaillet@wanadoo.fr> wrote:
>
> Le 11/03/2024 à 17:46, Pasha Tatashin a écrit :
> > There are two data types: "struct vm_struct" and "struct vm_stack" that
> > have the same local variable names: vm_stack, or vm, or s, which makes
> > code confusing to read.
> >
> > Change the code so the naming is consisent:
>
> Nit: consistent
>
> >
> > struct vm_struct is always called vm_area
> > struct vm_stack is always called vm_stack
> >
> > Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
> > ---
> > kernel/fork.c | 38 ++++++++++++++++++--------------------
> > 1 file changed, 18 insertions(+), 20 deletions(-)
> >
> > diff --git a/kernel/fork.c b/kernel/fork.c
> > index 32600bf2422a..60e812825a7a 100644
> > --- a/kernel/fork.c
> > +++ b/kernel/fork.c
> > @@ -192,12 +192,12 @@ struct vm_stack {
> > struct vm_struct *stack_vm_area;
> > };
> >
> > -static bool try_release_thread_stack_to_cache(struct vm_struct *vm)
> > +static bool try_release_thread_stack_to_cache(struct vm_struct *vm_area)
> > {
> > unsigned int i;
> >
> > for (i = 0; i < NR_CACHED_STACKS; i++) {
> > - if (this_cpu_cmpxchg(cached_stacks[i], NULL, vm) != NULL)
> > + if (this_cpu_cmpxchg(cached_stacks[i], NULL, vm_area) != NULL)
> > continue;
> > return true;
> > }
> > @@ -207,11 +207,12 @@ static bool try_release_thread_stack_to_cache(struct vm_struct *vm)
> > static void thread_stack_free_rcu(struct rcu_head *rh)
> > {
> > struct vm_stack *vm_stack = container_of(rh, struct vm_stack, rcu);
> > + struct vm_struct *vm_area = vm_stack->stack_vm_area;
> >
> > if (try_release_thread_stack_to_cache(vm_stack->stack_vm_area))
> > return;
> >
> > - vfree(vm_stack);
> > + vfree(vm_area->addr);
>
> This does not look like only a renaming of a variable. Is it?
>
> If no, should there be a Fixes tag and should it be detailed in the
> commit description?
This change is only for readability purposes. vm_stack is stored in
vm_area, so vfree(vm_stack) equals to vfree(vm_area->addr), but is
hard to read. I will add it to changelog.
>
> CJ
>
> > }
> >
> > static void thread_stack_delayed_free(struct task_struct *tsk)
> > @@ -228,12 +229,12 @@ static int free_vm_stack_cache(unsigned int cpu)
> > int i;
> >
> > for (i = 0; i < NR_CACHED_STACKS; i++) {
> > - struct vm_struct *vm_stack = cached_vm_stacks[i];
> > + struct vm_struct *vm_area = cached_vm_stacks[i];
> >
> > - if (!vm_stack)
> > + if (!vm_area)
> > continue;
> >
> > - vfree(vm_stack->addr);
> > + vfree(vm_area->addr);
> > cached_vm_stacks[i] = NULL;
> > }
> >
> > @@ -263,32 +264,29 @@ static int memcg_charge_kernel_stack(struct vm_struct *vm)
> >
> > static int alloc_thread_stack_node(struct task_struct *tsk, int node)
> > {
> > - struct vm_struct *vm;
> > + struct vm_struct *vm_area;
> > void *stack;
> > int i;
> >
> > for (i = 0; i < NR_CACHED_STACKS; i++) {
> > - struct vm_struct *s;
> > -
> > - s = this_cpu_xchg(cached_stacks[i], NULL);
> > -
> > - if (!s)
> > + vm_area = this_cpu_xchg(cached_stacks[i], NULL);
> > + if (!vm_area)
> > continue;
> >
> > /* Reset stack metadata. */
> > - kasan_unpoison_range(s->addr, THREAD_SIZE);
> > + kasan_unpoison_range(vm_area->addr, THREAD_SIZE);
> >
> > - stack = kasan_reset_tag(s->addr);
> > + stack = kasan_reset_tag(vm_area->addr);
> >
> > /* Clear stale pointers from reused stack. */
> > memset(stack, 0, THREAD_SIZE);
> >
> > - if (memcg_charge_kernel_stack(s)) {
> > - vfree(s->addr);
> > + if (memcg_charge_kernel_stack(vm_area)) {
> > + vfree(vm_area->addr);
> > return -ENOMEM;
> > }
> >
> > - tsk->stack_vm_area = s;
> > + tsk->stack_vm_area = vm_area;
> > tsk->stack = stack;
> > return 0;
> > }
> > @@ -306,8 +304,8 @@ static int alloc_thread_stack_node(struct task_struct *tsk, int node)
> > if (!stack)
> > return -ENOMEM;
> >
> > - vm = find_vm_area(stack);
> > - if (memcg_charge_kernel_stack(vm)) {
> > + vm_area = find_vm_area(stack);
> > + if (memcg_charge_kernel_stack(vm_area)) {
> > vfree(stack);
> > return -ENOMEM;
> > }
> > @@ -316,7 +314,7 @@ static int alloc_thread_stack_node(struct task_struct *tsk, int node)
> > * free_thread_stack() can be called in interrupt context,
> > * so cache the vm_struct.
> > */
> > - tsk->stack_vm_area = vm;
> > + tsk->stack_vm_area = vm_area;
> > stack = kasan_reset_tag(stack);
> > tsk->stack = stack;
> > return 0;
>
next prev parent reply other threads:[~2024-03-19 16:32 UTC|newest]
Thread overview: 98+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-11 16:46 [RFC 00/14] Dynamic Kernel Stacks Pasha Tatashin
2024-03-11 16:46 ` [RFC 01/14] task_stack.h: remove obsolete __HAVE_ARCH_KSTACK_END check Pasha Tatashin
2024-03-17 14:36 ` Christophe JAILLET
2024-03-17 15:13 ` Pasha Tatashin
2024-03-11 16:46 ` [RFC 02/14] fork: Clean-up ifdef logic around stack allocation Pasha Tatashin
2024-03-11 16:46 ` [RFC 03/14] fork: Clean-up naming of vm_strack/vm_struct variables in vmap stacks code Pasha Tatashin
2024-03-17 14:42 ` Christophe JAILLET
2024-03-19 16:32 ` Pasha Tatashin [this message]
2024-03-11 16:46 ` [RFC 04/14] fork: Remove assumption that vm_area->nr_pages equals to THREAD_SIZE Pasha Tatashin
2024-03-17 14:45 ` Christophe JAILLET
2024-03-17 15:14 ` Pasha Tatashin
2024-03-11 16:46 ` [RFC 05/14] fork: check charging success before zeroing stack Pasha Tatashin
2024-03-12 15:57 ` Kirill A. Shutemov
2024-03-12 16:52 ` Pasha Tatashin
2024-03-11 16:46 ` [RFC 06/14] fork: zero vmap stack using clear_page() instead of memset() Pasha Tatashin
2024-03-12 7:15 ` Nikolay Borisov
2024-03-12 16:53 ` Pasha Tatashin
2024-03-14 7:55 ` Christophe Leroy
2024-03-14 13:52 ` Pasha Tatashin
2024-03-17 14:48 ` Christophe JAILLET
2024-03-17 15:15 ` Pasha Tatashin
2024-03-11 16:46 ` [RFC 07/14] fork: use the first page in stack to store vm_stack in cached_stacks Pasha Tatashin
2024-03-11 16:46 ` [RFC 08/14] fork: separate vmap stack alloction and free calls Pasha Tatashin
2024-03-14 15:18 ` Jeff Xie
2024-03-14 17:14 ` Pasha Tatashin
2024-03-17 14:51 ` Christophe JAILLET
2024-03-17 15:15 ` Pasha Tatashin
2024-03-11 16:46 ` [RFC 09/14] mm/vmalloc: Add a get_vm_area_node() and vmap_pages_range_noflush() public functions Pasha Tatashin
2024-03-11 16:46 ` [RFC 10/14] fork: Dynamic Kernel Stacks Pasha Tatashin
2024-03-11 19:32 ` Randy Dunlap
2024-03-11 19:55 ` Pasha Tatashin
2024-03-11 16:46 ` [RFC 11/14] x86: add support for " Pasha Tatashin
2024-03-11 22:17 ` Andy Lutomirski
2024-03-11 23:10 ` Pasha Tatashin
2024-03-11 23:33 ` Thomas Gleixner
2024-03-11 23:34 ` Andy Lutomirski
2024-03-12 0:08 ` Pasha Tatashin
2024-03-12 0:23 ` Pasha Tatashin
2024-03-11 23:34 ` Dave Hansen
2024-03-11 23:41 ` Andy Lutomirski
2024-03-11 23:56 ` Nadav Amit
2024-03-12 0:02 ` Andy Lutomirski
2024-03-12 7:20 ` Nadav Amit
2024-03-12 0:53 ` Dave Hansen
2024-03-12 1:25 ` H. Peter Anvin
2024-03-12 2:16 ` Andy Lutomirski
2024-03-12 2:20 ` H. Peter Anvin
2024-03-12 21:58 ` Andi Kleen
2024-03-13 10:23 ` Thomas Gleixner
2024-03-13 13:43 ` Pasha Tatashin
2024-03-13 15:28 ` Pasha Tatashin
2024-03-13 16:12 ` Thomas Gleixner
2024-03-14 14:03 ` Pasha Tatashin
2024-03-14 18:26 ` Thomas Gleixner
2024-03-11 16:46 ` [RFC 12/14] task_stack.h: Clean-up stack_not_used() implementation Pasha Tatashin
2024-03-11 16:46 ` [RFC 13/14] task_stack.h: Add stack_not_used() support for dynamic stack Pasha Tatashin
2024-03-11 16:46 ` [RFC 14/14] fork: Dynamic Kernel Stack accounting Pasha Tatashin
2024-03-11 17:09 ` [RFC 00/14] Dynamic Kernel Stacks Mateusz Guzik
2024-03-11 18:58 ` Pasha Tatashin
2024-03-11 19:21 ` Mateusz Guzik
2024-03-11 19:55 ` Pasha Tatashin
2024-03-12 17:18 ` H. Peter Anvin
2024-03-12 19:45 ` Pasha Tatashin
2024-03-12 21:36 ` H. Peter Anvin
2024-03-14 19:05 ` Kent Overstreet
2024-03-14 19:23 ` Pasha Tatashin
2024-03-14 19:28 ` Kent Overstreet
2024-03-14 19:34 ` Pasha Tatashin
2024-03-14 19:49 ` Kent Overstreet
2024-03-12 22:18 ` David Laight
2024-03-14 19:43 ` Matthew Wilcox
2024-03-14 19:53 ` Kent Overstreet
2024-03-14 19:57 ` Matthew Wilcox
2024-03-14 19:58 ` Kent Overstreet
2024-03-15 3:13 ` Pasha Tatashin
2024-03-15 3:39 ` H. Peter Anvin
2024-03-16 19:17 ` Pasha Tatashin
2024-03-17 0:41 ` Matthew Wilcox
2024-03-17 1:32 ` Kent Overstreet
2024-03-17 14:19 ` Pasha Tatashin
2024-03-17 14:43 ` Brian Gerst
2024-03-17 16:15 ` Pasha Tatashin
2024-03-17 21:30 ` Brian Gerst
2024-03-18 14:59 ` Pasha Tatashin
2024-03-18 21:02 ` Brian Gerst
2024-03-19 14:56 ` Pasha Tatashin
2024-03-17 18:57 ` David Laight
2024-03-18 15:09 ` Pasha Tatashin
2024-03-18 15:13 ` Pasha Tatashin
2024-03-18 15:19 ` Matthew Wilcox
2024-03-18 15:30 ` Pasha Tatashin
2024-03-18 15:53 ` David Laight
2024-03-18 16:57 ` Pasha Tatashin
2024-03-18 15:38 ` David Laight
2024-03-18 17:00 ` Pasha Tatashin
2024-03-18 17:37 ` Pasha Tatashin
2024-03-15 4:17 ` H. Peter Anvin
2024-03-17 0:47 ` H. Peter Anvin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CA+CK2bB-7fUnMXcRLma60J-wFZ9Y-W45O0okU2fseuh-VxG8fA@mail.gmail.com \
--to=pasha.tatashin@soleen.com \
--cc=akpm@linux-foundation.org \
--cc=bp@alien8.de \
--cc=brauner@kernel.org \
--cc=bristot@redhat.com \
--cc=bsegall@google.com \
--cc=christophe.jaillet@wanadoo.fr \
--cc=dave.hansen@linux.intel.com \
--cc=dianders@chromium.org \
--cc=dietmar.eggemann@arm.com \
--cc=eric.devolder@oracle.com \
--cc=hca@linux.ibm.com \
--cc=hch@infradead.org \
--cc=hpa@zytor.com \
--cc=jacob.jun.pan@linux.intel.com \
--cc=jgg@ziepe.ca \
--cc=jpoimboe@kernel.org \
--cc=jroedel@suse.de \
--cc=juri.lelli@redhat.com \
--cc=kent.overstreet@linux.dev \
--cc=kinseyho@google.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=lstoakes@gmail.com \
--cc=luto@kernel.org \
--cc=mgorman@suse.de \
--cc=mic@digikod.net \
--cc=michael.christie@oracle.com \
--cc=mingo@redhat.com \
--cc=mjguzik@gmail.com \
--cc=mst@redhat.com \
--cc=npiggin@gmail.com \
--cc=peterz@infradead.org \
--cc=pmladek@suse.com \
--cc=rick.p.edgecombe@intel.com \
--cc=rostedt@goodmis.org \
--cc=surenb@google.com \
--cc=tglx@linutronix.de \
--cc=urezki@gmail.com \
--cc=vincent.guittot@linaro.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).