lkml.org 
[lkml]   [2005]   [Apr]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCH] meminfo: add Cached underflow check
Martin Hicks <mort@sgi.com> wrote:
>
> Working on some code lately I've been getting huge values
> for "Cached". The cause is that get_page_cache_size() is an
> approximate value, and for a sufficiently small returned value
> of get_page_cache_size() the value underflows.

OK..

I think I'd prefer to do it this way - it's simpler and the original patch
had a teeny race wrt changes in total_swapcache_pages.


diff -puN fs/proc/proc_misc.c~meminfo-add-cached-underflow-check fs/proc/proc_misc.c
--- 25/fs/proc/proc_misc.c~meminfo-add-cached-underflow-check Mon Apr 4 15:06:38 2005
+++ 25-akpm/fs/proc/proc_misc.c Mon Apr 4 15:10:24 2005
@@ -126,6 +126,7 @@ static int meminfo_read_proc(char *page,
unsigned long committed;
unsigned long allowed;
struct vmalloc_info vmi;
+ long cached;

get_page_state(&ps);
get_zone_counts(&active, &inactive, &free);
@@ -140,6 +141,10 @@ static int meminfo_read_proc(char *page,
allowed = ((totalram_pages - hugetlb_total_pages())
* sysctl_overcommit_ratio / 100) + total_swap_pages;

+ cached = get_page_cache_size() - total_swapcache_pages - i.bufferram;
+ if (cached < 0)
+ cached = 0;
+
get_vmalloc_info(&vmi);

/*
@@ -172,7 +177,7 @@ static int meminfo_read_proc(char *page,
K(i.totalram),
K(i.freeram),
K(i.bufferram),
- K(get_page_cache_size()-total_swapcache_pages-i.bufferram),
+ K(cached),
K(total_swapcache_pages),
K(active),
K(inactive),
_
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-04-06 13:31    [W:0.088 / U:0.532 seconds]
©2003-2014 Jasper Spaans. Advertise on this site