Hi,
Whilst analyzing the cleaner I added tracepoints called 'cleaner' and
'bufcache_take' to
track its behaviour.
For the sake of symmetry I've added one in bufcache_release() too and moved the
assignment
of 'pages' until after the KASSERT(), following the flow of bufcache_take().
Sample usage of these probes:
tracepoint:vfs:bufcache_take {
printf("bcache_take:%d(%s) flags: 0x%x cache: %d pages: %d\n",
tid, comm, arg0 , arg1, arg2);
}
tracepoint:vfs:bufcache_rel{
printf("bcache_rel:%d(%s) flags: 0x%x cache: %d pages: %d\n",
tid, comm, arg0, arg1, arg2);
}
tracepoint:vfs:cleaner{
printf("cleaner:%d(%s) flags: 0x%x pushed: %d lodirtypages: %d,
hidirtypages: %d\n",
tid, comm, arg0, arg1, arg2, arg3);
}
OK to commit this?
Index: dev/dt/dt_prov_static.c
===================================================================
RCS file: /cvs/src/sys/dev/dt/dt_prov_static.c,v
retrieving revision 1.4
diff -u -p -r1.4 dt_prov_static.c
--- dev/dt/dt_prov_static.c 13 Sep 2020 14:55:08 -0000 1.4
+++ dev/dt/dt_prov_static.c 14 Sep 2020 10:43:43 -0000
@@ -58,6 +58,13 @@ DT_STATIC_PROBE3(uvm, map_insert, "vaddr
DT_STATIC_PROBE3(uvm, map_remove, "vaddr_t", "vaddr_t", "vm_prot_t");
/*
+ * VFS
+ */
+DT_STATIC_PROBE3(vfs, bufcache_rel, "long", "int", "int64_t");
+DT_STATIC_PROBE3(vfs, bufcache_take, "long", "int", "int64_t");
+DT_STATIC_PROBE4(vfs, cleaner, "long", "int", "long", "long");
+
+/*
* List of all static probes
*/
struct dt_probe *dtps_static[] = {
@@ -76,6 +83,10 @@ struct dt_probe *dtps_static[] = {
&_DT_STATIC_P(uvm, fault),
&_DT_STATIC_P(uvm, map_insert),
&_DT_STATIC_P(uvm, map_remove),
+ /* VFS */
+ &_DT_STATIC_P(vfs, bufcache_rel),
+ &_DT_STATIC_P(vfs, bufcache_take),
+ &_DT_STATIC_P(vfs, cleaner),
};
int
Index: kern/vfs_bio.c
===================================================================
RCS file: /cvs/src/sys/kern/vfs_bio.c,v
retrieving revision 1.202
diff -u -p -r1.202 vfs_bio.c
--- kern/vfs_bio.c 12 Sep 2020 11:57:24 -0000 1.202
+++ kern/vfs_bio.c 14 Sep 2020 10:43:43 -0000
@@ -57,6 +57,7 @@
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/specdev.h>
+#include <sys/tracepoint.h>
#include <uvm/uvm_extern.h>
/* XXX Should really be in buf.h, but for uvm_constraint_range.. */
@@ -1209,6 +1210,9 @@ buf_daemon(void *arg)
}
while ((bp = bufcache_getdirtybuf())) {
+ TRACEPOINT(vfs, cleaner, bp->b_flags, pushed,
+ lodirtypages, hidirtypages);
+
if (UNCLEAN_PAGES < lodirtypages &&
bcstats.kvaslots_avail > 2 * RESERVE_SLOTS &&
pushed >= 16)
@@ -1693,6 +1697,9 @@ bufcache_take(struct buf *bp)
KASSERT((bp->cache < NUM_CACHES));
pages = atop(bp->b_bufsize);
+
+ TRACEPOINT(vfs, bufcache_take, bp->b_flags, bp->cache, pages);
+
struct bufcache *cache = &cleancache[bp->cache];
if (!ISSET(bp->b_flags, B_DELWRI)) {
if (ISSET(bp->b_flags, B_COLD)) {
@@ -1756,8 +1763,11 @@ bufcache_release(struct buf *bp)
int64_t pages;
struct bufcache *cache = &cleancache[bp->cache];
- pages = atop(bp->b_bufsize);
KASSERT(ISSET(bp->b_flags, B_BC));
+ pages = atop(bp->b_bufsize);
+
+ TRACEPOINT(vfs, bufcache_rel, bp->b_flags, bp->cache, pages);
+
if (fliphigh) {
if (ISSET(bp->b_flags, B_DMA) && bp->cache > 0)
panic("B_DMA buffer release from cache %d",
--
jasper
