debian/patches/pve/0006-swap-Tweak-meminfo-logic.patch

   1 From 1e92c18e409f37f79a24f61623b9d9c4d84e3280 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?St=C3=A9phane=20Graber?= <stgraber@ubuntu.com>
   3 Date: Thu, 5 Nov 2020 15:30:27 -0500
   4 Subject: [PATCH lxcfs 6/8] swap: Tweak meminfo logic
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
  10 ---
  11  src/proc_fuse.c | 30 +++++++++---------------------
  12  1 file changed, 9 insertions(+), 21 deletions(-)
  13
  14 diff --git a/src/proc_fuse.c b/src/proc_fuse.c
  15 index 002aac9..4c555ec 100644
  16 --- a/src/proc_fuse.c
  17 +++ b/src/proc_fuse.c
  18 @@ -1151,7 +1151,7 @@ static int proc_meminfo_read(char *buf, size_t size, off_t offset,
  19         __do_fclose FILE *f = NULL;
  20         struct fuse_context *fc = fuse_get_context();
  21         struct lxcfs_opts *opts = (struct lxcfs_opts *)fuse_get_context()->private_data;
  22 -       bool wants_swap = opts && !opts->swap_off && liblxcfs_can_use_swap(), host_swap = false;
  23 +       bool wants_swap = opts && !opts->swap_off && liblxcfs_can_use_swap();
  24         struct file_info *d = INTTYPE_TO_PTR(fi->fh);
  25         uint64_t memlimit = 0, memusage = 0, memswlimit = 0, memswusage = 0,
  26                  hosttotal = 0, swfree = 0, swusage = 0, swtotal = 0,
  27 @@ -1258,19 +1258,14 @@ static int proc_meminfo_read(char *buf, size_t size, off_t offset,
  28
  29                                 sscanf(line + STRLITERALLEN("SwapTotal:"), "%" PRIu64, &hostswtotal);
  30
  31 -                               /*
  32 -                                * If swtotal is 0 it should mean that
  33 -                                * memory.memsw.limit_in_bytes and
  34 -                                * memory.limit_in_bytes are both unlimited or
  35 -                                * both set to the same value. In both cases we
  36 -                                * have no idea what the technical swap limit
  37 -                                * is supposed to be (It's a shared limit
  38 -                                * anyway.) so fallback to the host's values in
  39 -                                * that case too.
  40 -                                */
  41 -                               if ((hostswtotal < swtotal) || swtotal == 0) {
  42 +                               /* The total amount of swap is always reported to be the
  43 +                                  lesser of the RAM+SWAP limit or the SWAP device size.
  44 +                                  This is because the kernel can swap as much as it
  45 +                                  wants and not only up to swtotal. */
  46 +
  47 +                               swtotal = memlimit + swtotal;
  48 +                               if (hostswtotal < swtotal) {
  49                                         swtotal = hostswtotal;
  50 -                                       host_swap = true;
  51                                 }
  52
  53                                 /* When swappiness is 0, pretend we can't swap. */
  54 @@ -1283,14 +1278,7 @@ static int proc_meminfo_read(char *buf, size_t size, off_t offset,
  55                         printme = lbuf;
  56                 } else if (startswith(line, "SwapFree:")) {
  57                         if (wants_swap) {
  58 -                               uint64_t hostswfree = 0;
  59 -
  60 -                               if (host_swap) {
  61 -                                       sscanf(line + STRLITERALLEN("SwapFree:"), "%" PRIu64, &hostswfree);
  62 -                                       swfree = hostswfree;
  63 -                               } else if (swtotal >= swusage) {
  64 -                                       swfree = swtotal - swusage;
  65 -                               }
  66 +                               swfree = swtotal - swusage;
  67                         }
  68
  69                         snprintf(lbuf, 100, "SwapFree:       %8" PRIu64 " kB\n", swfree);
  70 --
  71 2.20.1
  72