Re: [Crash-utility] Crash dump of RHEL5, what does "SHARED" memory represent in kmem -i output?
From: James Washer <washer(a)trlp.com>
To: Crash-utility(a)redhat.com
Subject: [Crash-utility] Crash dump of RHEL5, what does "SHARED"
memory represent in kmem -i output?
Message-ID: <E06C76EC-884A-4C02-9566-D647E0B575CA(a)trlp.com>
Content-Type: text/plain; charset=us-ascii
In the data below, what memory usage is reported as SHARED? Does this
imply SysV shared memory, or pages shared between processes, or something
else all together?
kmem-i
PAGES TOTAL PERCENTAGE
TOTAL MEM 9228936 35.2 GB ----
FREE 20260 79.1 MB 0% of TOTAL MEM
USED 9208676 35.1 GB 99% of TOTAL MEM
SHARED 9051322 34.5 GB 98% of TOTAL MEM
BUFFERS 151 604 KB 0% of TOTAL MEM
CACHED 2455 9.6 MB 0% of TOTAL MEM
SLAB 27419 107.1 MB 0% of TOTAL MEM
TOTAL HIGH 0 0 0% of TOTAL MEM
FREE HIGH 0 0 0% of TOTAL HIGH
TOTAL LOW 9228936 35.2 GB 100% of TOTAL MEM
FREE LOW 20260 79.1 MB 0% of TOTAL LOW
TOTAL SWAP 4194302 16 GB ----
SWAP USED 2294571 8.8 GB 54% of TOTAL SWAP
SWAP FREE 1899731 7.2 GB 45% of TOTAL SWAP
- jim
Hi Jim,
Purportedly it displays -- as the comment states:
/*
* Get shared pages from dump_mem_map(). Note that this is done
* differently than the kernel -- it just tallies the non-reserved
* pages that have a count of greater than 1.
*/
It has a check in there for the different usage of page->count,
where in certain kernel versions, -1 means 0.
Dave Anderson (on vacation)