At 2012-2-3 2:53, Dave Anderson wrote:
----- Original Message -----
That all being said, your patch does have merit -- presuming that
the meminfo.cache field *never* gets set elsewhere prior to entering
the dump_kmem_cache_xxx functions. I haven't taken the time to
verify that -- did you absolutely verify that?
It looks OK to use "if (si->cache)" in those 3 locations -- but it
would be safer to create/set a unique meminfo->flags bit for this
feature.
Thanks for your comments.
A new flag called "CACHE_SET" is created to inform the
dump_kmem_cache_xxx functions that "si->cache" has been set.
As you said in the previous mail, I agree that ~150000 individual slabs
rarely exist in a real-life scenario. However, ~150000 individual slabs
are used to illustrate the improvement clearly. Think about the
situation that I install a big module with some kmem_caches. I need to
check the state of each kmem_cache related to my module once some
operations are done. So the times of execution of "kmem -s <addr>" may
be even big. Time, obviouly, will be saved with my patch in such situation.
Dave
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Regards
Qiao Nuohan
diff --git a/memory.c b/memory.c
index 333d6e1..7a4c3ce 100755
--- a/memory.c
+++ b/memory.c
@@ -8306,7 +8306,13 @@ dump_kmem_cache(struct meminfo *si)
si->addrlist = (ulong *)GETBUF((vt->kmem_max_c_num+1) * sizeof(ulong));
cnt = 0;
- si->cache = cache_cache = symbol_value("cache_cache");
+ if (si->flags & CACHE_SET) {
+ readmem(si->cache+OFFSET(kmem_cache_s_c_nextp),
+ KVADDR, &cache_cache, sizeof(ulong),
+ "kmem_cache next", FAULT_ON_ERROR);
+ } else {
+ si->cache = cache_cache = symbol_value("cache_cache");
+ }
if (si->flags & ADDRESS_SPECIFIED) {
if (!(p1 = vaddr_to_kmem_cache(si->spec_addr, kbuf, VERBOSE))) {
@@ -8512,7 +8518,13 @@ dump_kmem_cache_percpu_v1(struct meminfo *si)
GETBUF(vt->kmem_max_limit * sizeof(ulong));
cnt = 0;
- si->cache = cache_cache = symbol_value("cache_cache");
+ if (si->flags & CACHE_SET) {
+ readmem(si->cache+OFFSET(kmem_cache_s_next),
+ KVADDR, &cache_cache, sizeof(ulong),
+ "kmem_cache_s next", FAULT_ON_ERROR);
+ } else {
+ si->cache = cache_cache = symbol_value("cache_cache");
+ }
if (si->flags & ADDRESS_SPECIFIED) {
if (!(p1 = vaddr_to_kmem_cache(si->spec_addr, kbuf, VERBOSE))) {
diff --git a/memory.c b/memory.c
index 95eefc9..333d6e1 100755
--- a/memory.c
+++ b/memory.c
@@ -3886,6 +3886,7 @@ get_task_mem_usage(ulong task, struct task_mem_usage *tm)
#define GET_SLUB_OBJECTS (ADDRESS_SPECIFIED << 20)
#define VMLIST_VERIFY (ADDRESS_SPECIFIED << 21)
#define SLAB_FIRST_NODE (ADDRESS_SPECIFIED << 22)
+#define CACHE_SET (ADDRESS_SPECIFIED << 23)
#define GET_ALL \
(GET_SHARED_PAGES|GET_TOTALRAM_PAGES|GET_BUFFERS_PAGES|GET_SLAB_PAGES)
@@ -4091,11 +4092,14 @@ cmd_kmem(void)
error(FATAL,
"only one kmem_cache reference is allowed\n");
meminfo.reqname = p1;
+ meminfo.cache = value[i];
+ meminfo.flags |= CACHE_SET;
if ((i+1) == spec_addr) { /* done? */
if (meminfo.calls++)
fprintf(fp, "\n");
vt->dump_kmem_cache(&meminfo);
}
+ meminfo.flags &= ~CACHE_SET;
} else {
meminfo.spec_addr = value[i];
meminfo.flags = ADDRESS_SPECIFIED;
@@ -7589,15 +7593,12 @@ is_kmem_cache_addr(ulong vaddr, char *kbuf)
cache_buf = GETBUF(SIZE(kmem_cache_s));
do {
- readmem(cache, KVADDR, cache_buf, SIZE(kmem_cache_s),
- "kmem_cache buffer", FAULT_ON_ERROR);
if (cache == vaddr) {
if (vt->kmem_cache_namelen) {
- BCOPY(cache_buf+name_offset, kbuf,
- vt->kmem_cache_namelen);
+ readmem(cache+name_offset, KVADDR, kbuf, vt->kmem_cache_namelen, "name array", FAULT_ON_ERROR);
} else {
- name = ULONG(cache_buf + name_offset);
+ readmem(cache+name_offset, KVADDR, &name, sizeof(name), "name", FAULT_ON_ERROR);
if (!read_string(name, kbuf, BUFSIZE-1)) {
if (vt->flags &
(PERCPU_KMALLOC_V1|PERCPU_KMALLOC_V2))
@@ -7615,7 +7616,8 @@ is_kmem_cache_addr(ulong vaddr, char *kbuf)
return kbuf;
}
- cache = ULONG(cache_buf + next_offset);
+ readmem(cache+next_offset, KVADDR, &cache, sizeof(long),
+ "kmem_cache_s next", FAULT_ON_ERROR);
if (vt->flags & (PERCPU_KMALLOC_V1|PERCPU_KMALLOC_V2))
cache -= next_offset;
@@ -8733,9 +8735,15 @@ dump_kmem_cache_percpu_v2(struct meminfo *si)
cnt = 0;
- get_symbol_data("cache_chain", sizeof(ulong), &si->cache);
- si->cache -= OFFSET(kmem_cache_s_next);
- cache_end = symbol_value("cache_chain");
+ if (si->flags & CACHE_SET) {
+ readmem(si->cache+OFFSET(kmem_cache_s_next),
+ KVADDR, &cache_end, sizeof(ulong),
+ "kmem_cache_s next", FAULT_ON_ERROR);
+ } else {
+ get_symbol_data("cache_chain", sizeof(ulong), &si->cache);
+ si->cache -= OFFSET(kmem_cache_s_next);
+ cache_end = symbol_value("cache_chain");
+ }
if (si->flags & ADDRESS_SPECIFIED) {
if (!(p1 = vaddr_to_kmem_cache(si->spec_addr, kbuf, VERBOSE))) {
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