6:08 p.m.
Fix for the "kmem -i" option on Linux 5.0 and later kernels that
contain commit ca79b0c211af63fa3276f0e3fd7dd9ada2439839, titled
"mm: convert totalram_pages and totalhigh_pages variables to atomic".
Without the patch, the command prints some incorrect values, and
besides doesn't print high/low memory information on kernels which
are configured with CONFIG_HIGHMEM.
crash> kmem -i
PAGES TOTAL PERCENTAGE
TOTAL MEM -4395174638254716088 53602483503169.4 GB ----
FREE 398314 1.5 GB 0% of TOTAL MEM
USED -4395174638255114402 53602483503167.9 GB 0% of TOTAL MEM
...
Tested with 5.0 and 4.20 Fedora kernels for x86_64 and x86.
Signed-off-by: Kazuhito Hagio <k-hagio(a)ab.jp.nec.com>
---
memory.c | 75 +++++++++++++++++++++++++++-----------------------------
1 file changed, 36 insertions(+), 39 deletions(-)
diff --git a/memory.c b/memory.c
index 9c1019a..ab561b3 100644
--- a/memory.c
+++ b/memory.c
@@ -910,26 +910,40 @@ vm_init(void)
if (IS_VMALLOC_ADDR(vt->mem_map))
vt->flags |= V_MEM_MAP;
vt->total_pages = BTOP(VTOP(vt->high_memory));
- switch (get_syment_array("totalram_pages", sp_array, 2))
- {
- case 1:
- get_symbol_data("totalram_pages", sizeof(ulong),
- &vt->totalram_pages);
- break;
- case 2:
- if (!(readmem(sp_array[0]->value, KVADDR,
- &value1, sizeof(ulong),
- "totalram_pages #1", RETURN_ON_ERROR)))
+
+ if (symbol_exists("_totalram_pages")) {
+ readmem(symbol_value("_totalram_pages") +
+ OFFSET(atomic_t_counter), KVADDR,
+ &vt->totalram_pages, sizeof(ulong),
+ "_totalram_pages", FAULT_ON_ERROR);
+ } else {
+ switch (get_syment_array("totalram_pages", sp_array, 2))
+ {
+ case 1:
+ get_symbol_data("totalram_pages", sizeof(ulong),
+ &vt->totalram_pages);
break;
- if (!(readmem(sp_array[1]->value, KVADDR,
- &value2, sizeof(ulong),
- "totalram_pages #2", RETURN_ON_ERROR)))
- break;
- vt->totalram_pages = MAX(value1, value2);
- break;
+ case 2:
+ if (!(readmem(sp_array[0]->value, KVADDR,
+ &value1, sizeof(ulong),
+ "totalram_pages #1", RETURN_ON_ERROR)))
+ break;
+ if (!(readmem(sp_array[1]->value, KVADDR,
+ &value2, sizeof(ulong),
+ "totalram_pages #2", RETURN_ON_ERROR)))
+ break;
+ vt->totalram_pages = MAX(value1, value2);
+ break;
+ }
}
- if (symbol_exists("totalhigh_pages")) {
+ if (symbol_exists("_totalhigh_pages")) {
+ readmem(symbol_value("_totalhigh_pages") +
+ OFFSET(atomic_t_counter), KVADDR,
+ &vt->totalhigh_pages, sizeof(ulong),
+ "_totalhigh_pages", FAULT_ON_ERROR);
+ vt->total_pages += vt->totalhigh_pages;
+ } else if (symbol_exists("totalhigh_pages")) {
switch (get_syment_array("totalhigh_pages", sp_array, 2))
{
case 1:
@@ -8169,7 +8183,6 @@ dump_kmeminfo(void)
long nr_file_pages, nr_slab;
ulong swapper_space_nrpages;
ulong pct;
- ulong value1, value2;
uint tmp;
struct meminfo meminfo;
struct gnu_request req;
@@ -8177,7 +8190,6 @@ dump_kmeminfo(void)
ulong get_totalram;
ulong get_buffers;
ulong get_slabs;
- struct syment *sp_array[2];
char buf[BUFSIZE];
@@ -8210,7 +8222,8 @@ dump_kmeminfo(void)
* Prior to 2.3.36, count all mem_map pages minus the reserved ones.
* From 2.3.36 onwards, use "totalram_pages" if set.
*/
- if (symbol_exists("totalram_pages")) {
+ if (symbol_exists("totalram_pages") ||
+ symbol_exists("_totalram_pages")) {
totalram_pages = vt->totalram_pages ?
vt->totalram_pages : get_totalram;
} else
@@ -8362,25 +8375,9 @@ dump_kmeminfo(void)
fprintf(fp, "%13s %7ld %11s %3ld%% of TOTAL MEM\n",
"SLAB", get_slabs, pages_to_size(get_slabs, buf), pct);
- if (symbol_exists("totalhigh_pages")) {
- switch (get_syment_array("totalhigh_pages", sp_array, 2))
- {
- case 1:
- get_symbol_data("totalhigh_pages", sizeof(ulong),
- &totalhigh_pages);
- break;
- case 2:
- if (!(readmem(sp_array[0]->value, KVADDR,
- &value1, sizeof(ulong),
- "totalhigh_pages #1", RETURN_ON_ERROR)))
- break;
- if (!(readmem(sp_array[1]->value, KVADDR,
- &value2, sizeof(ulong),
- "totalhigh_pages #2", RETURN_ON_ERROR)))
- break;
- totalhigh_pages = MAX(value1, value2);
- break;
- }
+ if (symbol_exists("totalhigh_pages") ||
+ symbol_exists("_totalhigh_pages")) {
+ totalhigh_pages = vt->totalhigh_pages;
pct = totalhigh_pages ?
(totalhigh_pages * 100)/totalram_pages : 0;
--
2.17.0