Re: [patch 3/21] scaled writeback throttling levels

From: William Lee Irwin III (wli@holomorphy.com)
Date: Wed Aug 14 2002 - 03:40:08 EST


On Sun, Aug 11, 2002 at 12:38:32AM -0700, Andrew Morton wrote:
> (resend)
> get_page_state() is showing up on profiles on some big machines. It is
> a quite expensive function and it is being called too often.
> The patch replaces the hardwired RATELIMIT_PAGES with a calculated
> amount based on the amount of memory in the machine and the number of
> CPUs.

dbench 256 on 16x/16G numaq:

Throughput 50.5397 MB/sec (NB=63.1747 MB/sec 505.397 MBit/sec) 256 procs

c013bf74 5827289 74.4428 .text.lock.highmem
c013b7d0 797024 10.1819 kunmap_high
c013b5dc 482436 6.16306 kmap_high
c012e53c 87883 1.12269 file_read_actor
c0114820 65764 0.840126 scheduler_tick
c013bcbc 32857 0.419744 blk_queue_bounce
c013564c 31874 0.407186 rmqueue
c012f260 29442 0.376118 generic_file_write
c01113b8 28706 0.366715 smp_apic_timer_interrupt
c0143d1c 26503 0.338572 block_prepare_write
c0105394 20555 0.262587 default_idle
c012dec0 19920 0.254475 unlock_page
c014333c 17401 0.222295 __block_prepare_write
c013b558 16545 0.21136 flush_all_zero_pkmaps
c0135d28 14959 0.191099 page_cache_release
c013fb30 11923 0.152315 generic_file_llseek
c013429c 11059 0.141277 lru_cache_add
c0135b10 10277 0.131287 __alloc_pages
c0140124 9841 0.125717 vfs_write
c0143dc8 8732 0.11155 generic_commit_write
c012dcb4 8051 0.10285 add_to_page_cache
c016d620 7884 0.100717 ext2_get_block
-
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/



This archive was generated by hypermail 2b29 : Thu Aug 15 2002 - 22:00:36 EST