On Wed, Jun 25, 2014 at 12:41:17PM -0700, Motohiro Kosaki wrote: > > > > -----Original Message----- > > From: Rafael Aquini [mailto:aquini@xxxxxxxxxx] > > Sent: Wednesday, June 25, 2014 2:40 PM > > To: linux-mm@xxxxxxxxx > > Cc: Andrew Morton; Rik van Riel; Mel Gorman; Johannes Weiner; Motohiro Kosaki JP; linux-kernel@xxxxxxxxxxxxxxx > > Subject: [PATCH] mm: export NR_SHMEM via sysinfo(2) / si_meminfo() interfaces > > > > This patch leverages the addition of explicit accounting for pages used by shmem/tmpfs -- "4b02108 mm: oom analysis: add shmem > > vmstat" -- in order to make the users of sysinfo(2) and si_meminfo*() friends aware of that vmstat entry consistently across the > > interfaces. > > Why? Because we do not report consistently across the interfaces we declare exporting that data. Check sysinfo(2) manpage, for instance: [...] struct sysinfo { long uptime; /* Seconds since boot */ unsigned long loads[3]; /* 1, 5, and 15 minute load averages */ unsigned long totalram; /* Total usable main memory size */ unsigned long freeram; /* Available memory size */ unsigned long sharedram; /* Amount of shared memory */ <<<<< [...] userspace tools resorting to sysinfo() syscall will get a hardcoded 0 for shared memory which is reported differently from /proc/meminfo. Also, si_meminfo() & si_meminfo_node() are utilized within the kernel to gather statistics for /proc/meminfo & friends, and so we can leverage collecting sharedmem from those calls as well, just as we do for totalram, freeram & bufferram. Regards, -- Rafael > Traditionally sysinfo.sharedram was not used for shmem. It was totally strange semantics and completely outdated feature. > So, we may reuse it for another purpose. But I'm not sure its benefit. > > Why don't you use /proc/meminfo? > I'm afraid userland programs get a confusion. > > > > > > Signed-off-by: Rafael Aquini <aquini@xxxxxxxxxx> > > --- > > drivers/base/node.c | 2 +- > > fs/proc/meminfo.c | 2 +- > > mm/page_alloc.c | 3 ++- > > 3 files changed, 4 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/base/node.c b/drivers/base/node.c index 8f7ed99..c6d3ae0 100644 > > --- a/drivers/base/node.c > > +++ b/drivers/base/node.c > > @@ -126,7 +126,7 @@ static ssize_t node_read_meminfo(struct device *dev, > > nid, K(node_page_state(nid, NR_FILE_PAGES)), > > nid, K(node_page_state(nid, NR_FILE_MAPPED)), > > nid, K(node_page_state(nid, NR_ANON_PAGES)), > > - nid, K(node_page_state(nid, NR_SHMEM)), > > + nid, K(i.sharedram), > > nid, node_page_state(nid, NR_KERNEL_STACK) * > > THREAD_SIZE / 1024, > > nid, K(node_page_state(nid, NR_PAGETABLE)), diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c index > > 7445af0..aa1eee0 100644 > > --- a/fs/proc/meminfo.c > > +++ b/fs/proc/meminfo.c > > @@ -168,7 +168,7 @@ static int meminfo_proc_show(struct seq_file *m, void *v) > > K(global_page_state(NR_WRITEBACK)), > > K(global_page_state(NR_ANON_PAGES)), > > K(global_page_state(NR_FILE_MAPPED)), > > - K(global_page_state(NR_SHMEM)), > > + K(i.sharedram), > > K(global_page_state(NR_SLAB_RECLAIMABLE) + > > global_page_state(NR_SLAB_UNRECLAIMABLE)), > > K(global_page_state(NR_SLAB_RECLAIMABLE)), > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 20d17f8..f72ea38 100644 > > --- a/mm/page_alloc.c > > +++ b/mm/page_alloc.c > > @@ -3040,7 +3040,7 @@ static inline void show_node(struct zone *zone) void si_meminfo(struct sysinfo *val) { > > val->totalram = totalram_pages; > > - val->sharedram = 0; > > + val->sharedram = global_page_state(NR_SHMEM); > > val->freeram = global_page_state(NR_FREE_PAGES); > > val->bufferram = nr_blockdev_pages(); > > val->totalhigh = totalhigh_pages; > > @@ -3060,6 +3060,7 @@ void si_meminfo_node(struct sysinfo *val, int nid) > > for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) > > managed_pages += pgdat->node_zones[zone_type].managed_pages; > > val->totalram = managed_pages; > > + val->sharedram = node_page_state(nid, NR_SHMEM); > > val->freeram = node_page_state(nid, NR_FREE_PAGES); #ifdef CONFIG_HIGHMEM > > val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].managed_pages; > > -- > > 1.9.3 > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>