| Message ID | 20230330114956.20342-5-kirill.shutemov@linux.intel.com |
|---|---|
| State | New |
| Headers | show |
| Series | mm, x86/cc: Implement support for unaccepted memory | expand |
On 3/30/23 13:49, Kirill A. Shutemov wrote: > Write amount of memory to accept into the new sysfs handle > /sys/kernel/mm/page_alloc/accept_memory. > > Write 'all' to the handle to accept all memory in the system. > > It can be used to implement background memory accepting from userspace. > It is also useful for debugging. > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Somewhat similarly to patch 3, I'd think we don't need this patch in mainline without clear usecases first, although it's good to post for testing/debugging. > --- > mm/page_alloc.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 64 insertions(+) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 509a93b7e5af..07e16e9b49c4 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -7343,6 +7343,45 @@ static bool __free_unaccepted(struct page *page) > return true; > } > > +static ssize_t accept_memory_store(struct kobject *kobj, > + struct kobj_attribute *attr, > + const char *buf, size_t count) > +{ > + unsigned long to_accept = 0; > + struct zone *zone; > + char *retptr; > + > + if (sysfs_streq(buf, "all")) { > + to_accept = ULONG_MAX; > + } else { > + to_accept = memparse(buf, &retptr); > + > + /* Get rid of trailing whitespace, including '\n' */ > + retptr = skip_spaces(retptr); > + > + if (*retptr != 0 || to_accept == 0) > + return -EINVAL; > + } > + > + for_each_populated_zone(zone) { > + while (try_to_accept_memory_one(zone)) { > + if (to_accept <= PAGE_SIZE << MAX_ORDER) > + return count; > + > + to_accept -= PAGE_SIZE << MAX_ORDER; > + } > + } > + > + return count; > +} > + > +static struct kobj_attribute accept_memory_attr = __ATTR_WO(accept_memory); > + > +static struct attribute *page_alloc_attr[] = { > + &accept_memory_attr.attr, > + NULL > +}; > + > #else > > static bool page_contains_unaccepted(struct page *page, unsigned int order) > @@ -7366,3 +7405,28 @@ static bool __free_unaccepted(struct page *page) > } > > #endif /* CONFIG_UNACCEPTED_MEMORY */ > + > +static const struct attribute_group page_alloc_attr_group = { > +#ifdef CONFIG_UNACCEPTED_MEMORY > + .attrs = page_alloc_attr, > +#endif > +}; > + > +static int __init page_alloc_init_sysfs(void) > +{ > + struct kobject *page_alloc_kobj; > + int err; > + > + page_alloc_kobj = kobject_create_and_add("page_alloc", mm_kobj); > + if (!page_alloc_kobj) > + return -ENOMEM; > + > + err = sysfs_create_group(page_alloc_kobj, &page_alloc_attr_group); > + if (err) { > + kobject_put(page_alloc_kobj); > + return err; > + } > + > + return 0; > +} > +late_initcall(page_alloc_init_sysfs);
On Mon, Apr 03, 2023 at 03:43:32PM +0200, Vlastimil Babka wrote: > On 3/30/23 13:49, Kirill A. Shutemov wrote: > > Write amount of memory to accept into the new sysfs handle > > /sys/kernel/mm/page_alloc/accept_memory. > > > > Write 'all' to the handle to accept all memory in the system. > > > > It can be used to implement background memory accepting from userspace. > > It is also useful for debugging. > > > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > > Somewhat similarly to patch 3, I'd think we don't need this patch in > mainline without clear usecases first, although it's good to post for > testing/debugging. I thought about it as a way to implement #3 from 02/14 commit message: users who want to accept all memory in background can use the mechanism. But, again, we can leave out until later.
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 509a93b7e5af..07e16e9b49c4 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -7343,6 +7343,45 @@ static bool __free_unaccepted(struct page *page) return true; } +static ssize_t accept_memory_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) +{ + unsigned long to_accept = 0; + struct zone *zone; + char *retptr; + + if (sysfs_streq(buf, "all")) { + to_accept = ULONG_MAX; + } else { + to_accept = memparse(buf, &retptr); + + /* Get rid of trailing whitespace, including '\n' */ + retptr = skip_spaces(retptr); + + if (*retptr != 0 || to_accept == 0) + return -EINVAL; + } + + for_each_populated_zone(zone) { + while (try_to_accept_memory_one(zone)) { + if (to_accept <= PAGE_SIZE << MAX_ORDER) + return count; + + to_accept -= PAGE_SIZE << MAX_ORDER; + } + } + + return count; +} + +static struct kobj_attribute accept_memory_attr = __ATTR_WO(accept_memory); + +static struct attribute *page_alloc_attr[] = { + &accept_memory_attr.attr, + NULL +}; + #else static bool page_contains_unaccepted(struct page *page, unsigned int order) @@ -7366,3 +7405,28 @@ static bool __free_unaccepted(struct page *page) } #endif /* CONFIG_UNACCEPTED_MEMORY */ + +static const struct attribute_group page_alloc_attr_group = { +#ifdef CONFIG_UNACCEPTED_MEMORY + .attrs = page_alloc_attr, +#endif +}; + +static int __init page_alloc_init_sysfs(void) +{ + struct kobject *page_alloc_kobj; + int err; + + page_alloc_kobj = kobject_create_and_add("page_alloc", mm_kobj); + if (!page_alloc_kobj) + return -ENOMEM; + + err = sysfs_create_group(page_alloc_kobj, &page_alloc_attr_group); + if (err) { + kobject_put(page_alloc_kobj); + return err; + } + + return 0; +} +late_initcall(page_alloc_init_sysfs);
Write amount of memory to accept into the new sysfs handle /sys/kernel/mm/page_alloc/accept_memory. Write 'all' to the handle to accept all memory in the system. It can be used to implement background memory accepting from userspace. It is also useful for debugging. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> --- mm/page_alloc.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+)