On Wed, Apr 27, 2022 at 05:20:29PM -0400, Johannes Weiner wrote: > On Wed, Apr 27, 2022 at 01:29:34PM -0700, Minchan Kim wrote: > > Hi Johannes, > > > > On Wed, Apr 27, 2022 at 12:00:15PM -0400, Johannes Weiner wrote: > > > Currently it requires poking at debugfs to figure out the size and > > > population of the zswap cache on a host. There are no counters for > > > reads and writes against the cache. As a result, it's difficult to > > > understand zswap behavior on production systems. > > > > > > Print zswap memory consumption and how many pages are zswapped out in > > > /proc/meminfo. Count zswapouts and zswapins in /proc/vmstat. > > > > > > Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx> > > > --- > > > fs/proc/meminfo.c | 7 +++++++ > > > include/linux/swap.h | 5 +++++ > > > include/linux/vm_event_item.h | 4 ++++ > > > mm/vmstat.c | 4 ++++ > > > mm/zswap.c | 13 ++++++------- > > > 5 files changed, 26 insertions(+), 7 deletions(-) > > > > > > diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c > > > index 6fa761c9cc78..6e89f0e2fd20 100644 > > > --- a/fs/proc/meminfo.c > > > +++ b/fs/proc/meminfo.c > > > @@ -86,6 +86,13 @@ static int meminfo_proc_show(struct seq_file *m, void *v) > > > > > > show_val_kb(m, "SwapTotal: ", i.totalswap); > > > show_val_kb(m, "SwapFree: ", i.freeswap); > > > +#ifdef CONFIG_ZSWAP > > > + seq_printf(m, "Zswap: %8lu kB\n", > > > + (unsigned long)(zswap_pool_total_size >> 10)); > > > + seq_printf(m, "Zswapped: %8lu kB\n", > > > + (unsigned long)atomic_read(&zswap_stored_pages) << > > > + (PAGE_SHIFT - 10)); > > > +#endif > > > > I agree it would be very handy to have the memory consumption in meminfo > > > > https://lore.kernel.org/all/YYwZXrL3Fu8%2FvLZw@xxxxxxxxxx/ > > > > If we really go this Zswap only metric instead of general term > > "Compressed", I'd like to post maybe "Zram:" with same reason > > in this patchset. Do you think that's better idea instead of > > introducing general term like "Compressed:" or something else? > > I'm fine with changing it to Compressed. If somebody cares about a > more detailed breakdown, we can add Zswap, Zram subsets as needed. Thanks! Please consider ZSWPIN to rename more general term, too. > > From 8e9e2d6490b7082c41743fbdb9ffd2db4e3ce962 Mon Sep 17 00:00:00 2001 > From: Johannes Weiner <hannes@xxxxxxxxxxx> > Date: Wed, 27 Apr 2022 17:15:15 -0400 > Subject: [PATCH] mm: zswap: add basic meminfo and vmstat coverage fix fix > > Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx> > --- > Documentation/filesystems/proc.rst | 7 ++++--- > fs/proc/meminfo.c | 2 +- > 2 files changed, 5 insertions(+), 4 deletions(-) > > diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst > index 8b5a94cfa722..93edcf233464 100644 > --- a/Documentation/filesystems/proc.rst > +++ b/Documentation/filesystems/proc.rst > @@ -964,7 +964,7 @@ Example output. You may not have all of these fields. > Mlocked: 0 kB > SwapTotal: 0 kB > SwapFree: 0 kB > - Zswap: 1904 kB > + Compressed: 1904 kB > Zswapped: 7792 kB > Dirty: 12 kB > Writeback: 0 kB > @@ -1057,8 +1057,9 @@ SwapTotal > SwapFree > Memory which has been evicted from RAM, and is temporarily > on the disk > -Zswap > - Memory consumed by the zswap backend (compressed size) > +Compressed > + Memory consumed by compression backends, such as zswap > + (compressed size) > Zswapped > Amount of anonymous memory stored in zswap (original size) > Dirty > diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c > index 6e89f0e2fd20..554d6f230e67 100644 > --- a/fs/proc/meminfo.c > +++ b/fs/proc/meminfo.c > @@ -87,7 +87,7 @@ static int meminfo_proc_show(struct seq_file *m, void *v) > show_val_kb(m, "SwapTotal: ", i.totalswap); > show_val_kb(m, "SwapFree: ", i.freeswap); > #ifdef CONFIG_ZSWAP > - seq_printf(m, "Zswap: %8lu kB\n", > + seq_printf(m, "Compressed: %8lu kB\n", > (unsigned long)(zswap_pool_total_size >> 10)); > seq_printf(m, "Zswapped: %8lu kB\n", > (unsigned long)atomic_read(&zswap_stored_pages) << > -- > 2.35.3 >
