raw device and linux scheduling performance weirdness

Hi, I ran some really trivial raw disk performance tests on 2.4.0 using the raw disk support in it. I seem to be getting some really strange performance results. My program opens up a raw device, then does a sequence of sequential/random reads/writes on the raw device using pread/pwrite. I put ti

pthreads related issues

Hi, I think I forgot to include the subject on the email I sent last time. Not sure how many people saw it. I'm trying to send this message again... I have two questions on Linux pthread related issues. Would anyone be able to help? 1. Does any one have some suggestions (pointers) on good kern

No Subject

Hi, I have two questions on Linux pthread related issues. Would anyone be able to help? 1. Does any one have some suggestions (pointers) on good kernel Linux thread libraries? 2. We ran multi-threaded application using Linux pthread library on 2-way SMP and UP intel platforms (with both 2.2 a

Re: test11-pre6

ler, void *private) ====== Ying Chen - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/

[patch] nfsd optimizations for test10 (yet another try)

Neil, Here is a set of fixes and answers to you questions/points. The new patch was tested in my own environment again and worked fine. 1/ Why did you change nfsd_busy into an atomic_t? It is only ever used or updated inside the Big-Kernel-Lock, so it doesn't need to be atomic. I think

[patch] nfsd optimizations for test10 (recoded to use list_head)

ct raparms *) &hash_list[REQHASH(ino, dev)]; +while ((ra = ra->p_hash_next) != rahead) { + if ((ra->p_ino == ino) && (ra->p_dev == dev)) { + /* Do LRU reordering */ + list_del(&ra->p_lru); + list_add(&ra->p_l

Re: [patch] nfsd optimizations for test10

1/ Do you have any stats showing what sort of speedup this gives - I'm curious. I don't have the exact timing stats to show the improvements, but I do have some stats that I gathered when running SPEC SFS. Basically with the default racache scheme which only keeps 80 entries in the table

problems with sync_all_inode() in prune_icache() and kupdate()

Hi, I'm wondering if someone can tell me why sync_all_inodes() is called in prune_icache(). sync_all_inodes() can cause problems in some situations when memory is short and shrink_icache_memory() is called. For instance, when the system is really short of memory, do_try_to_free_pages() is invoked

[patch] wakeup_bdflush related fixes and nfsd optimizations for test10

scanning the table (even though the table is small), the hash table-based is much more effective and fast. I have generated the patch for test10 and tested it. (See attached file: a) Ying Chen [EMAIL PROTECTED] IBM Almaden Research Center a

[patch] nfsd optimizations for test10

Hi, I made some optimizations on racache in nfsd in test10. The idea is to replace with existing fixed length table for readahead cache in NFSD with a hash table. The old racache is essentially ineffective in dealing with large # of files, and yet eats CPU cycles in scanning the table (even thoug

Re: VM in v2.4.0test9

I'd second that this is most likely a VM related problem. Last few days I sent you an example that I would make system hang simply by doing a mkfs on 90 GB file system. This happens when low 1GB memory is used up (but I still have high 1GB available). I think David probably ran into the same prob