This patch introduces new fields to per-mount and global stats,
and export them to user space.
@page_alloc -- number of pages allocated from buddy to buffer cache
@page_free -- number of pages freed to buddy from buffer cache
@kbb_alloc -- number of BBs allocated from kmalloc slab to buffer cache
@kbb_free -- number of BBs freed to kmalloc slab from buffer cache
@vbb_alloc -- number of BBs allocated from vmalloc system to buffer cache
@vbb_free -- number of BBs freed to vmalloc system from buffer cache
By looking at above stats fields, user space can easily know the buffer
cache usage.
Signed-off-by: Wengang Wang <wen.gang.wang@xxxxxxxxxx>
---
fs/xfs/xfs_buf.c | 15 +++++++++++----
fs/xfs/xfs_stats.c | 16 ++++++++++++++++
fs/xfs/xfs_stats.h | 8 ++++++++
3 files changed, 35 insertions(+), 4 deletions(-)
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 1a2b3f06fa71..db3cb94eabee 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -113,12 +113,17 @@ xfs_buf_free(
if (!xfs_buftarg_is_mem(bp->b_target) && size >= PAGE_SIZE)
mm_account_reclaimed_pages(howmany(size, PAGE_SHIFT));
- if (is_vmalloc_addr(bp->b_addr))
+ if (is_vmalloc_addr(bp->b_addr)) {
vfree(bp->b_addr);
- else if (bp->b_flags & _XBF_KMEM)
+ XFS_STATS_ADD(bp->b_mount, xs_buf_vbb_free, bp->b_length);
+ } else if (bp->b_flags & _XBF_KMEM) {
kfree(bp->b_addr);
- else
+ XFS_STATS_ADD(bp->b_mount, xs_buf_kbb_free, bp->b_length);
+ } else {
folio_put(virt_to_folio(bp->b_addr));
+ XFS_STATS_ADD(bp->b_mount, xs_buf_page_free,
+ BBTOB(bp->b_length) >> PAGE_SHIFT);
+ }
call_rcu(&bp->b_rcu, xfs_buf_free_callback);
}
@@ -147,6 +152,7 @@ xfs_buf_alloc_kmem(
return -ENOMEM;
}
bp->b_flags |= _XBF_KMEM;
+ XFS_STATS_ADD(bp->b_mount, xs_buf_kbb_alloc, bp->b_length);
trace_xfs_buf_backing_kmem(bp, _RET_IP_);
return 0;
}
@@ -232,6 +238,7 @@ xfs_buf_alloc_backing_mem(
}
bp->b_addr = folio_address(folio);
trace_xfs_buf_backing_folio(bp, _RET_IP_);
+ XFS_STATS_ADD(bp->b_mount, xs_buf_page_alloc, size >> PAGE_SHIFT);
return 0;
fallback:
@@ -244,7 +251,7 @@ xfs_buf_alloc_backing_mem(
XFS_STATS_INC(bp->b_mount, xb_page_retries);
memalloc_retry_wait(gfp_mask);
}
-
+ XFS_STATS_ADD(bp->b_mount, xs_buf_vbb_alloc, bp->b_length);
trace_xfs_buf_backing_vmalloc(bp, _RET_IP_);
return 0;
}
diff --git a/fs/xfs/xfs_stats.c b/fs/xfs/xfs_stats.c
index 35c7fb3ba324..a0f6813dc782 100644
--- a/fs/xfs/xfs_stats.c
+++ b/fs/xfs/xfs_stats.c
@@ -24,6 +24,12 @@ int xfs_stats_format(struct xfsstats __percpu *stats, char *buf)
uint64_t xs_write_bytes = 0;
uint64_t xs_read_bytes = 0;
uint64_t defer_relog = 0;
+ uint64_t pg_alloc = 0;
+ uint64_t pg_free = 0;
+ uint64_t kbb_alloc = 0;
+ uint64_t kbb_free = 0;
+ uint64_t vbb_alloc = 0;
+ uint64_t vbb_free = 0;
static const struct xstats_entry {
char *desc;
@@ -77,6 +83,12 @@ int xfs_stats_format(struct xfsstats __percpu *stats, char *buf)
xs_write_bytes += per_cpu_ptr(stats, i)->s.xs_write_bytes;
xs_read_bytes += per_cpu_ptr(stats, i)->s.xs_read_bytes;
defer_relog += per_cpu_ptr(stats, i)->s.defer_relog;
+ pg_alloc += per_cpu_ptr(stats, i)->s.xs_buf_page_alloc;
+ pg_free += per_cpu_ptr(stats, i)->s.xs_buf_page_free;
+ kbb_alloc += per_cpu_ptr(stats, i)->s.xs_buf_kbb_alloc;
+ kbb_free += per_cpu_ptr(stats, i)->s.xs_buf_kbb_free;
+ vbb_alloc += per_cpu_ptr(stats, i)->s.xs_buf_vbb_alloc;
+ vbb_free += per_cpu_ptr(stats, i)->s.xs_buf_vbb_free;
}
len += scnprintf(buf + len, PATH_MAX-len, "xpc %llu %llu %llu\n",
@@ -89,6 +101,10 @@ int xfs_stats_format(struct xfsstats __percpu *stats, char *buf)
#else
0);
#endif
+ len += scnprintf(buf + len, PATH_MAX-len,
+ "cache %llu %llu %llu %llu %llu %llu\n",
+ pg_alloc, pg_free, kbb_alloc, kbb_free,
+ vbb_alloc, vbb_free);
return len;
}
diff --git a/fs/xfs/xfs_stats.h b/fs/xfs/xfs_stats.h
index 15ba1abcf253..5e186880d8d0 100644
--- a/fs/xfs/xfs_stats.h
+++ b/fs/xfs/xfs_stats.h
@@ -143,6 +143,14 @@ struct __xfsstats {
uint64_t xs_write_bytes;
uint64_t xs_read_bytes;
uint64_t defer_relog;
+
+ /* number of pages/bbs allocated/freed in buffer cache */
+ uint64_t xs_buf_page_alloc;
+ uint64_t xs_buf_page_free;
+ uint64_t xs_buf_kbb_alloc;
+ uint64_t xs_buf_kbb_free;
+ uint64_t xs_buf_vbb_alloc;
+ uint64_t xs_buf_vbb_free;
};
#define xfsstats_offset(f) (offsetof(struct __xfsstats, f)/sizeof(uint32_t))
--
2.39.5 (Apple Git-154)
