From: Anthony Yznaga <anthony.yznaga@oracle.com> To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: willy@infradead.org, corbet@lwn.net, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, rppt@kernel.org, akpm@linux-foundation.org, hughd@google.com, ebiederm@xmission.com, keescook@chromium.org, ardb@kernel.org, nivedita@alum.mit.edu, jroedel@suse.de, masahiroy@kernel.org, nathan@kernel.org, terrelln@fb.com, vincenzo.frascino@arm.com, martin.b.radev@gmail.com, andreyknvl@google.com, daniel.kiper@oracle.com, rafael.j.wysocki@intel.com, dan.j.williams@intel.com, Jonathan.Cameron@huawei.com, bhe@redhat.com, rminnich@gmail.com, ashish.kalra@amd.com, guro@fb.com, hannes@cmpxchg.org, mhocko@kernel.org, iamjoonsoo.kim@lge.com, vbabka@suse.cz, alex.shi@linux.alibaba.com, david@redhat.com, richard.weiyang@gmail.com, vdavydov.dev@gmail.com, graf@amazon.com, jason.zeng@intel.com, lei.l.li@intel.com, daniel.m.jordan@oracle.com, steven.sistare@oracle.com, linux-fsdevel@vger.kernel.org, linux-doc@vger.kernel.org, kexec@lists.infradead.org Subject: [RFC v2 19/43] mm: PKRAM: allow preserved memory to be freed from userspace Date: Tue, 30 Mar 2021 14:35:54 -0700 [thread overview] Message-ID: <1617140178-8773-20-git-send-email-anthony.yznaga@oracle.com> (raw) In-Reply-To: <1617140178-8773-1-git-send-email-anthony.yznaga@oracle.com> To free all space utilized for preserved memory, one can write 0 to /sys/kernel/pkram. This will destroy all PKRAM nodes that are not currently being read or written. Originally-by: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Anthony Yznaga <anthony.yznaga@oracle.com> --- mm/pkram.c | 39 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 38 insertions(+), 1 deletion(-) diff --git a/mm/pkram.c b/mm/pkram.c index dcf84ba785a7..8700fd77dc67 100644 --- a/mm/pkram.c +++ b/mm/pkram.c @@ -493,6 +493,32 @@ static void pkram_truncate_node(struct pkram_node *node) node->obj_pfn = 0; } +/* + * Free all nodes that are not under operation. + */ +static void pkram_truncate(void) +{ + struct page *page, *tmp; + struct pkram_node *node; + LIST_HEAD(dispose); + + mutex_lock(&pkram_mutex); + list_for_each_entry_safe(page, tmp, &pkram_nodes, lru) { + node = page_address(page); + if (!(node->flags & PKRAM_ACCMODE_MASK)) + list_move(&page->lru, &dispose); + } + mutex_unlock(&pkram_mutex); + + while (!list_empty(&dispose)) { + page = list_first_entry(&dispose, struct page, lru); + list_del(&page->lru); + node = page_address(page); + pkram_truncate_node(node); + pkram_free_page(node); + } +} + static void pkram_add_link(struct pkram_link *link, struct pkram_data_stream *pds) { __u64 link_pfn = page_to_pfn(virt_to_page(link)); @@ -1233,8 +1259,19 @@ static ssize_t show_pkram_sb_pfn(struct kobject *kobj, return sprintf(buf, "%lx\n", pfn); } +static ssize_t store_pkram_sb_pfn(struct kobject *kobj, + struct kobj_attribute *attr, const char *buf, size_t count) +{ + int val; + + if (kstrtoint(buf, 0, &val) || val) + return -EINVAL; + pkram_truncate(); + return count; +} + static struct kobj_attribute pkram_sb_pfn_attr = - __ATTR(pkram, 0444, show_pkram_sb_pfn, NULL); + __ATTR(pkram, 0644, show_pkram_sb_pfn, store_pkram_sb_pfn); static struct attribute *pkram_attrs[] = { &pkram_sb_pfn_attr.attr, -- 1.8.3.1
WARNING: multiple messages have this Message-ID (diff)
From: Anthony Yznaga <anthony.yznaga@oracle.com> To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: willy@infradead.org, corbet@lwn.net, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, rppt@kernel.org, akpm@linux-foundation.org, hughd@google.com, ebiederm@xmission.com, keescook@chromium.org, ardb@kernel.org, nivedita@alum.mit.edu, jroedel@suse.de, masahiroy@kernel.org, nathan@kernel.org, terrelln@fb.com, vincenzo.frascino@arm.com, martin.b.radev@gmail.com, andreyknvl@google.com, daniel.kiper@oracle.com, rafael.j.wysocki@intel.com, dan.j.williams@intel.com, Jonathan.Cameron@huawei.com, bhe@redhat.com, rminnich@gmail.com, ashish.kalra@amd.com, guro@fb.com, hannes@cmpxchg.org, mhocko@kernel.org, iamjoonsoo.kim@lge.com, vbabka@suse.cz, alex.shi@linux.alibaba.com, david@redhat.com, richard.weiyang@gmail.com, vdavydov.dev@gmail.com, graf@amazon.com, jason.zeng@intel.com, lei.l.li@intel.com, daniel.m.jordan@oracle.com, steven.sistare@oracle.com, linux-fsdevel@vger.kernel.org, linux-doc@vger.kernel.org, kexec@lists.infradead.org Subject: [RFC v2 19/43] mm: PKRAM: allow preserved memory to be freed from userspace Date: Tue, 30 Mar 2021 14:35:54 -0700 [thread overview] Message-ID: <1617140178-8773-20-git-send-email-anthony.yznaga@oracle.com> (raw) In-Reply-To: <1617140178-8773-1-git-send-email-anthony.yznaga@oracle.com> To free all space utilized for preserved memory, one can write 0 to /sys/kernel/pkram. This will destroy all PKRAM nodes that are not currently being read or written. Originally-by: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Anthony Yznaga <anthony.yznaga@oracle.com> --- mm/pkram.c | 39 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 38 insertions(+), 1 deletion(-) diff --git a/mm/pkram.c b/mm/pkram.c index dcf84ba785a7..8700fd77dc67 100644 --- a/mm/pkram.c +++ b/mm/pkram.c @@ -493,6 +493,32 @@ static void pkram_truncate_node(struct pkram_node *node) node->obj_pfn = 0; } +/* + * Free all nodes that are not under operation. + */ +static void pkram_truncate(void) +{ + struct page *page, *tmp; + struct pkram_node *node; + LIST_HEAD(dispose); + + mutex_lock(&pkram_mutex); + list_for_each_entry_safe(page, tmp, &pkram_nodes, lru) { + node = page_address(page); + if (!(node->flags & PKRAM_ACCMODE_MASK)) + list_move(&page->lru, &dispose); + } + mutex_unlock(&pkram_mutex); + + while (!list_empty(&dispose)) { + page = list_first_entry(&dispose, struct page, lru); + list_del(&page->lru); + node = page_address(page); + pkram_truncate_node(node); + pkram_free_page(node); + } +} + static void pkram_add_link(struct pkram_link *link, struct pkram_data_stream *pds) { __u64 link_pfn = page_to_pfn(virt_to_page(link)); @@ -1233,8 +1259,19 @@ static ssize_t show_pkram_sb_pfn(struct kobject *kobj, return sprintf(buf, "%lx\n", pfn); } +static ssize_t store_pkram_sb_pfn(struct kobject *kobj, + struct kobj_attribute *attr, const char *buf, size_t count) +{ + int val; + + if (kstrtoint(buf, 0, &val) || val) + return -EINVAL; + pkram_truncate(); + return count; +} + static struct kobj_attribute pkram_sb_pfn_attr = - __ATTR(pkram, 0444, show_pkram_sb_pfn, NULL); + __ATTR(pkram, 0644, show_pkram_sb_pfn, store_pkram_sb_pfn); static struct attribute *pkram_attrs[] = { &pkram_sb_pfn_attr.attr, -- 1.8.3.1 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
next prev parent reply other threads:[~2021-03-30 21:28 UTC|newest] Thread overview: 94+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-03-30 21:35 [RFC v2 00/43] PKRAM: Preserved-over-Kexec RAM Anthony Yznaga 2021-03-30 21:35 ` Anthony Yznaga 2021-03-30 21:35 ` [RFC v2 01/43] mm: add PKRAM API stubs and Kconfig Anthony Yznaga 2021-03-30 21:35 ` Anthony Yznaga 2021-03-31 18:43 ` Randy Dunlap 2021-03-31 18:43 ` Randy Dunlap 2021-03-31 20:28 ` Anthony Yznaga 2021-03-31 20:28 ` Anthony Yznaga 2021-03-30 21:35 ` [RFC v2 02/43] mm: PKRAM: implement node load and save functions Anthony Yznaga 2021-03-30 21:35 ` Anthony Yznaga 2021-03-30 21:35 ` [RFC v2 03/43] mm: PKRAM: implement object " Anthony Yznaga 2021-03-30 21:35 ` Anthony Yznaga 2021-03-30 21:35 ` [RFC v2 04/43] mm: PKRAM: implement page stream operations Anthony Yznaga 2021-03-30 21:35 ` Anthony Yznaga 2021-03-30 21:35 ` [RFC v2 05/43] mm: PKRAM: support preserving transparent hugepages Anthony Yznaga 2021-03-30 21:35 ` Anthony Yznaga 2021-03-30 21:35 ` [RFC v2 06/43] mm: PKRAM: implement byte stream operations Anthony Yznaga 2021-03-30 21:35 ` Anthony Yznaga 2021-03-30 21:35 ` [RFC v2 07/43] mm: PKRAM: link nodes by pfn before reboot Anthony Yznaga 2021-03-30 21:35 ` Anthony Yznaga 2021-03-30 21:35 ` [RFC v2 08/43] mm: PKRAM: introduce super block Anthony Yznaga 2021-03-30 21:35 ` Anthony Yznaga 2021-03-30 21:35 ` [RFC v2 09/43] PKRAM: track preserved pages in a physical mapping pagetable Anthony Yznaga 2021-03-30 21:35 ` Anthony Yznaga 2021-03-30 21:35 ` [RFC v2 10/43] PKRAM: pass a list of preserved ranges to the next kernel Anthony Yznaga 2021-03-30 21:35 ` Anthony Yznaga 2021-03-30 21:35 ` [RFC v2 11/43] PKRAM: prepare for adding preserved ranges to memblock reserved Anthony Yznaga 2021-03-30 21:35 ` Anthony Yznaga 2021-03-30 21:35 ` [RFC v2 12/43] mm: PKRAM: reserve preserved memory at boot Anthony Yznaga 2021-03-30 21:35 ` Anthony Yznaga 2021-03-30 21:35 ` [RFC v2 13/43] PKRAM: free the preserved ranges list Anthony Yznaga 2021-03-30 21:35 ` Anthony Yznaga 2021-03-30 21:35 ` [RFC v2 14/43] PKRAM: prevent inadvertent use of a stale superblock Anthony Yznaga 2021-03-30 21:35 ` Anthony Yznaga 2021-03-30 21:35 ` [RFC v2 15/43] PKRAM: provide a way to ban pages from use by PKRAM Anthony Yznaga 2021-03-30 21:35 ` Anthony Yznaga 2021-03-30 21:35 ` [RFC v2 16/43] kexec: PKRAM: prevent kexec clobbering preserved pages in some cases Anthony Yznaga 2021-03-30 21:35 ` Anthony Yznaga 2021-03-30 21:35 ` [RFC v2 17/43] PKRAM: provide a way to check if a memory range has preserved pages Anthony Yznaga 2021-03-30 21:35 ` Anthony Yznaga 2021-03-30 21:35 ` [RFC v2 18/43] kexec: PKRAM: avoid clobbering already " Anthony Yznaga 2021-03-30 21:35 ` Anthony Yznaga 2021-03-30 21:35 ` Anthony Yznaga [this message] 2021-03-30 21:35 ` [RFC v2 19/43] mm: PKRAM: allow preserved memory to be freed from userspace Anthony Yznaga 2021-03-30 21:35 ` [RFC v2 20/43] PKRAM: disable feature when running the kdump kernel Anthony Yznaga 2021-03-30 21:35 ` Anthony Yznaga 2021-03-30 21:35 ` [RFC v2 21/43] x86/KASLR: PKRAM: support physical kaslr Anthony Yznaga 2021-03-30 21:35 ` Anthony Yznaga 2021-03-30 21:35 ` [RFC v2 22/43] x86/boot/compressed/64: use 1GB pages for mappings Anthony Yznaga 2021-03-30 21:35 ` Anthony Yznaga 2021-03-30 21:35 ` [RFC v2 23/43] mm: shmem: introduce shmem_insert_page Anthony Yznaga 2021-03-30 21:35 ` Anthony Yznaga 2021-03-30 21:35 ` [RFC v2 24/43] mm: shmem: enable saving to PKRAM Anthony Yznaga 2021-03-30 21:35 ` Anthony Yznaga 2021-03-30 21:36 ` [RFC v2 25/43] mm: shmem: prevent swapping of PKRAM-enabled tmpfs pages Anthony Yznaga 2021-03-30 21:36 ` Anthony Yznaga 2021-03-30 21:36 ` [RFC v2 26/43] mm: shmem: specify the mm to use when inserting pages Anthony Yznaga 2021-03-30 21:36 ` Anthony Yznaga 2021-03-30 21:36 ` [RFC v2 27/43] mm: shmem: when inserting, handle pages already charged to a memcg Anthony Yznaga 2021-03-30 21:36 ` Anthony Yznaga 2021-03-30 21:36 ` [RFC v2 28/43] x86/mm/numa: add numa_isolate_memblocks() Anthony Yznaga 2021-03-30 21:36 ` Anthony Yznaga 2021-03-30 21:36 ` [RFC v2 29/43] PKRAM: ensure memblocks with preserved pages init'd for numa Anthony Yznaga 2021-03-30 21:36 ` Anthony Yznaga 2021-03-30 21:36 ` [RFC v2 30/43] memblock: PKRAM: mark memblocks that contain preserved pages Anthony Yznaga 2021-03-30 21:36 ` Anthony Yznaga 2021-03-30 21:36 ` [RFC v2 31/43] memblock, mm: defer initialization of " Anthony Yznaga 2021-03-30 21:36 ` Anthony Yznaga 2021-03-30 21:36 ` [RFC v2 32/43] shmem: preserve shmem files a chunk at a time Anthony Yznaga 2021-03-30 21:36 ` Anthony Yznaga 2021-03-30 21:36 ` [RFC v2 33/43] PKRAM: atomically add and remove link pages Anthony Yznaga 2021-03-30 21:36 ` Anthony Yznaga 2021-03-30 21:36 ` [RFC v2 34/43] shmem: PKRAM: multithread preserving and restoring shmem pages Anthony Yznaga 2021-03-30 21:36 ` Anthony Yznaga 2021-03-30 21:36 ` [RFC v2 35/43] shmem: introduce shmem_insert_pages() Anthony Yznaga 2021-03-30 21:36 ` Anthony Yznaga 2021-03-30 21:36 ` [RFC v2 36/43] PKRAM: add support for loading pages in bulk Anthony Yznaga 2021-03-30 21:36 ` Anthony Yznaga 2021-03-30 21:36 ` [RFC v2 37/43] shmem: PKRAM: enable bulk loading of preserved pages into shmem Anthony Yznaga 2021-03-30 21:36 ` Anthony Yznaga 2021-03-30 21:36 ` [RFC v2 38/43] mm: implement splicing a list of pages to the LRU Anthony Yznaga 2021-03-30 21:36 ` Anthony Yznaga 2021-03-30 21:36 ` [RFC v2 39/43] shmem: optimize adding pages to the LRU in shmem_insert_pages() Anthony Yznaga 2021-03-30 21:36 ` Anthony Yznaga 2021-03-30 21:36 ` [RFC v2 40/43] shmem: initial support for adding multiple pages to pagecache Anthony Yznaga 2021-03-30 21:36 ` Anthony Yznaga 2021-03-30 21:36 ` [RFC v2 41/43] XArray: add xas_export_node() and xas_import_node() Anthony Yznaga 2021-03-30 21:36 ` Anthony Yznaga 2021-03-30 21:36 ` [RFC v2 42/43] shmem: reduce time holding xa_lock when inserting pages Anthony Yznaga 2021-03-30 21:36 ` Anthony Yznaga 2021-03-30 21:36 ` [RFC v2 43/43] PKRAM: improve index alignment of pkram_link entries Anthony Yznaga 2021-03-30 21:36 ` Anthony Yznaga 2021-06-05 13:39 ` [RFC v2 00/43] PKRAM: Preserved-over-Kexec RAM Pavel Tatashin 2021-06-05 13:39 ` Pavel Tatashin
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