Curious how efficient the dcache is?
Curious how well the fat cache is doing?
Say no more..
This patch is a few revisions old (made off 2.1.99 but patches cleanly into
the latest and greatest kernels) but it still works great.
Appends 3 lines to the /proc/stat file with dcache, buffer cache, and fat cache
hit and miss counts.. a trivial userspace program can figure out the
percentages for you (which I might be coding later tonite)
Have fun with it.. let me know your experiences with it.
-- Which is worse, ignorance or apathy? Who knows? Who cares? IBM: It may be slow, but at least it's expensive. Mir is the Russian word for 'duck-tape' - Dennis Miller You've won Solitaire! For your high score to register, Win95 must be restarted.--z6Eq5LdranGa6ru8 Content-Type: text/plain; charset=us-ascii Content-Description: /proc/stat addition for statistics Content-Disposition: attachment; filename="2.1.99-hitmiss.patch"
--- linux/fs/fat/cache.c.virgin Tue May 5 01:52:58 1998 +++ linux/fs/fat/cache.c Tue May 5 01:54:13 1998 @@ -10,6 +10,7 @@ #include <linux/string.h> #include <linux/stat.h> #include <linux/fat_cvf.h> +#include <linux/kernel_stat.h> #include "msbuffer.h" @@ -155,8 +156,10 @@ #ifdef DEBUG printk("cache hit: %d (%d)\n",walk->file_cluster,*d_clu); #endif + kstat.fat_hit++; if ((*f_clu = walk->file_cluster) == cluster) return; } + kstat.fat_miss++; #ifdef DEBUG printk("cache miss\n"); #endif --- linux/fs/proc/array.c.virgin Tue May 5 01:57:24 1998 +++ linux/fs/proc/array.c Tue May 5 02:29:15 1998 @@ -296,10 +296,23 @@ len += sprintf(buffer + len, "\nctxt %u\n" "btime %lu\n" - "processes %lu\n", + "processes %lu\n" + "bufcache %lu %lu\n" + "dircache %lu %lu\n" + "fatcache %lu %lu\n" + "smbcache %lu %lu\n", kstat.context_swtch, xtime.tv_sec - jiffies / HZ, - total_forks); + total_forks, + kstat.buf_hit, + kstat.buf_miss, + kstat.dir_hit, + kstat.dir_miss, + kstat.fat_hit, + kstat.fat_miss, + kstat.smb_hit, + kstat.smb_miss +); return len; } --- linux/fs/smbfs/cache.c.virgin Tue May 5 01:50:38 1998 +++ linux/fs/smbfs/cache.c Tue May 5 01:52:23 1998 @@ -15,6 +15,7 @@ #include <linux/errno.h> #include <linux/dirent.h> #include <linux/smb_fs.h> +#include <linux/kernel_stat.h> #include <asm/page.h> @@ -248,6 +249,11 @@ #endif break; } + if (offset == 0) + kstat.smb_miss++; + else + kstat.smb_hit++; + return offset; } --- linux/fs/dcache.c.virgin Tue May 5 01:35:02 1998 +++ linux/fs/dcache.c Tue May 5 01:39:04 1998 @@ -18,6 +18,7 @@ #include <linux/fs.h> #include <linux/malloc.h> #include <linux/init.h> +#include <linux/kernel_stat.h> #include <asm/uaccess.h> @@ -560,8 +561,10 @@ if (memcmp(dentry->d_name.name, str, len)) continue; } + kstat.dir_hit++; return dget(dentry); } + kstat.dir_miss++; return NULL; } --- linux/fs/buffer.c.virgin Tue May 5 01:39:20 1998 +++ linux/fs/buffer.c Tue May 5 02:15:14 1998 @@ -43,6 +43,7 @@ #include <linux/sysrq.h> #include <linux/file.h> #include <linux/quotaops.h> +#include <linux/kernel_stat.h> #include <asm/system.h> #include <asm/uaccess.h> @@ -585,6 +586,12 @@ next = tmp; break; } + + if (next) + kstat.buf_hit++; + else + kstat.buf_miss++; + return next; } --- linux/include/linux/kernel_stat.h.virgin Tue May 5 01:32:11 1998 +++ linux/include/linux/kernel_stat.h Tue May 5 01:54:42 1998 @@ -31,6 +31,10 @@ unsigned int ierrors, oerrors; unsigned int collisions; unsigned int context_swtch; + unsigned int buf_hit, buf_miss; + unsigned int dir_hit, dir_miss; + unsigned int fat_hit, fat_miss; + unsigned int smb_hit, smb_miss; }; extern struct kernel_stat kstat;
--z6Eq5LdranGa6ru8--
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