Messages in this thread | | | Date | Mon, 20 Dec 2004 16:10:45 +0100 | From | Andrea Arcangeli <> | Subject | Re: Reducing inode cache usage on 2.4? |
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On Mon, Dec 20, 2004 at 10:46:04AM -0200, Marcelo Tosatti wrote: > On Mon, Dec 20, 2004 at 01:47:46PM +0000, James Pearson wrote: > > I've tested the patch on my test setup - running a 'find $disk -type f' > > and a cat of large files to /dev/null at the same time does indeed > > reduce the size of the inode and dentry caches considerably - the first > > column numbers for fs_inode, linvfs_icache and dentry_cache in > > /proc/slabinfo hover at about 400-600 (over 900000 previously). > > > > However, is this going a bit to far the other way? When I boot the > > machine with 4Gb RAM, the inode and dentry caches are squeezed to the > > same amounts, but it may be the case that it would be more beneficial to > > have more in the inode and dentry caches? i.e. I guess some sort of > > tunable factor that limits the minimum size of the inode and dentry > > caches in this case? > > One can increase vm_vfs_scan_ratio if required, but hopefully this change > will benefit all workloads. > > Andrew, Andrea, do you think of any workloads which might be hurt by this change?
I wouldn't touch the defaults, but the sysctl is there so if you've a strange workload you can tune for it.
There's nothing wrong with dcache/icache growing a lot. A cat of a large file is polluting the cache, so that's not a workload that should shrink the dcache/icache. I'd prefer a feedback based on a real useful workload before even considering touching the defaults at this time. - 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/
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