From 59ae96ffc3a6731c3b85f9925e07e893d392e814 Mon Sep 17 00:00:00 2001 From: Christian Hansen Date: Fri, 17 Aug 2018 15:45:02 -0700 Subject: [PATCH] tools/vm/page-types.c: add support for idle page tracking Add a flag which causes page-types to use the kernels's idle page tracking to mark pages idle. As the tool already prints the idle flag if set, subsequent runs will show which pages have been accessed since last run. [akpm@linux-foundation.org: simplify mark_page_idle()] [chansen3@cisco.com: reorganize mark_page_idle() logic, add docs] Link: http://lkml.kernel.org/r/20180706172237.21691-1-chansen3@cisco.com Link: http://lkml.kernel.org/r/20180612153223.13174-1-chansen3@cisco.com Signed-off-by: Christian Hansen Reviewed-by: Andrew Morton Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- .../admin-guide/mm/idle_page_tracking.rst | 5 ++ tools/vm/page-types.c | 47 ++++++++++++++++++- 2 files changed, 51 insertions(+), 1 deletion(-) diff --git a/Documentation/admin-guide/mm/idle_page_tracking.rst b/Documentation/admin-guide/mm/idle_page_tracking.rst index 6f7b7ca1add3..df9394fb39c2 100644 --- a/Documentation/admin-guide/mm/idle_page_tracking.rst +++ b/Documentation/admin-guide/mm/idle_page_tracking.rst @@ -65,6 +65,11 @@ workload one should: are not reclaimable, he or she can filter them out using ``/proc/kpageflags``. +The page-types tool in the tools/vm directory can be used to assist in this. +If the tool is run initially with the appropriate option, it will mark all the +queried pages as idle. Subsequent runs of the tool can then show which pages have +their idle flag cleared in the interim. + See :ref:`Documentation/admin-guide/mm/pagemap.rst ` for more information about ``/proc/pid/pagemap``, ``/proc/kpageflags``, and ``/proc/kpagecgroup``. diff --git a/tools/vm/page-types.c b/tools/vm/page-types.c index 14ebd1695223..30cb0a0713ff 100644 --- a/tools/vm/page-types.c +++ b/tools/vm/page-types.c @@ -78,6 +78,8 @@ #define PROC_KPAGECOUNT "/proc/kpagecount" #define PROC_KPAGECGROUP "/proc/kpagecgroup" +#define SYS_KERNEL_MM_PAGE_IDLE "/sys/kernel/mm/page_idle/bitmap" + /* [32-] kernel hacking assistances */ #define KPF_RESERVED 32 #define KPF_MLOCKED 33 @@ -169,6 +171,7 @@ static const char * const debugfs_known_mountpoints[] = { static int opt_raw; /* for kernel developers */ static int opt_list; /* list pages (in ranges) */ +static int opt_mark_idle; /* set accessed bit */ static int opt_no_summary; /* don't show summary */ static pid_t opt_pid; /* process to walk */ const char *opt_file; /* file or directory path */ @@ -198,6 +201,7 @@ static int pagemap_fd; static int kpageflags_fd; static int kpagecount_fd = -1; static int kpagecgroup_fd = -1; +static int page_idle_fd = -1; static int opt_hwpoison; static int opt_unpoison; @@ -587,6 +591,30 @@ static int unpoison_page(unsigned long offset) return 0; } +static int mark_page_idle(unsigned long offset) +{ + static unsigned long off; + static uint64_t buf; + int len; + + if ((offset / 64 == off / 64) || buf == 0) { + buf |= 1UL << (offset % 64); + off = offset; + return 0; + } + + len = pwrite(page_idle_fd, &buf, 8, 8 * (off / 64)); + if (len < 0) { + perror("mark page idle"); + return len; + } + + buf = 1UL << (offset % 64); + off = offset; + + return 0; +} + /* * page frame walker */ @@ -635,6 +663,9 @@ static void add_page(unsigned long voffset, unsigned long offset, if (opt_unpoison) unpoison_page(offset); + if (opt_mark_idle) + mark_page_idle(offset); + if (opt_list == 1) show_page_range(voffset, offset, 1, flags, cgroup, mapcnt); else if (opt_list == 2) @@ -783,6 +814,9 @@ static void walk_addr_ranges(void) else walk_task(opt_offset[i], opt_size[i]); + if (opt_mark_idle) + mark_page_idle(0); + close(kpageflags_fd); } @@ -813,6 +847,7 @@ static void usage(void) " -c|--cgroup path|@inode Walk pages within memory cgroup\n" " -p|--pid pid Walk process address space\n" " -f|--file filename Walk file address space\n" +" -i|--mark-idle Mark pages idle\n" " -l|--list Show page details in ranges\n" " -L|--list-each Show page details one by one\n" " -C|--list-cgroup Show cgroup inode for pages\n" @@ -1221,6 +1256,7 @@ static const struct option opts[] = { { "bits" , 1, NULL, 'b' }, { "cgroup" , 1, NULL, 'c' }, { "describe" , 1, NULL, 'd' }, + { "mark-idle" , 0, NULL, 'i' }, { "list" , 0, NULL, 'l' }, { "list-each" , 0, NULL, 'L' }, { "list-cgroup", 0, NULL, 'C' }, @@ -1240,7 +1276,7 @@ int main(int argc, char *argv[]) page_size = getpagesize(); while ((c = getopt_long(argc, argv, - "rp:f:a:b:d:c:ClLMNXxF:h", + "rp:f:a:b:d:c:CilLMNXxF:h", opts, NULL)) != -1) { switch (c) { case 'r': @@ -1267,6 +1303,9 @@ int main(int argc, char *argv[]) case 'd': describe_flags(optarg); exit(0); + case 'i': + opt_mark_idle = 1; + break; case 'l': opt_list = 1; break; @@ -1308,6 +1347,9 @@ int main(int argc, char *argv[]) if (opt_list && opt_list_mapcnt) kpagecount_fd = checked_open(PROC_KPAGECOUNT, O_RDONLY); + if (opt_mark_idle && opt_file) + page_idle_fd = checked_open(SYS_KERNEL_MM_PAGE_IDLE, O_RDWR); + if (opt_list && opt_pid) printf("voffset\t"); if (opt_list && opt_file) @@ -1341,5 +1383,8 @@ int main(int argc, char *argv[]) if (opt_list_mapcnt) close(kpagecount_fd); + if (page_idle_fd >= 0) + close(page_idle_fd); + return 0; } -- 2.34.1