Re: xfs: does mkfs.xfs require fancy switches to get decent performance? (was Tux3 Report: How fast can we fsync?)

2015-05-12 Thread Howard Chu
e performance now. http://symas.com/mdb/ondisk/ I look forward to testing Tux3 when usable code shows up in a public repo. -- -- Howard Chu CTO, Symas Corp. http://www.symas.com Director, Highland Sun http://highlandsun.com/hyc/ Chief Architect, OpenLDAP http://www.openldap.org/p

Re: xfs: does mkfs.xfs require fancy switches to get decent performance? (was Tux3 Report: How fast can we fsync?)

2015-04-30 Thread Howard Chu
Daniel Phillips wrote: On 04/30/2015 07:28 AM, Howard Chu wrote: You're reading into it what isn't there. Spreading over the disk isn't (just) about avoiding fragmentation - it's about delivering consistent and predictable latency. It is undeniable that if you start by

Re: xfs: does mkfs.xfs require fancy switches to get decent performance? (was Tux3 Report: How fast can we fsync?)

2015-04-30 Thread Howard Chu
mpact will be negative, the only question is to what degree. -- -- Howard Chu CTO, Symas Corp. http://www.symas.com Director, Highland Sun http://highlandsun.com/hyc/ Chief Architect, OpenLDAP http://www.openldap.org/project/ -- To unsubscribe from this list: send the line &

Re: [PATCH] n_tty: Remove LINEMODE support

2015-01-20 Thread Howard Chu
Howard Chu wrote: Peter Hurley wrote: On 01/19/2015 02:43 PM, Howard Chu wrote: The fact that EXTPROC can be manually unset is by design. Quoting from the original again: stty.diff: This file contains the changes needed for the stty(1) program to report on the current status of the

Re: [PATCH] n_tty: Remove LINEMODE support

2015-01-20 Thread Howard Chu
Peter Hurley wrote: On 01/19/2015 02:43 PM, Howard Chu wrote: The fact that EXTPROC can be manually unset is by design. Quoting from the original again: stty.diff: This file contains the changes needed for the stty(1) program to report on the current status of the TS_EXTPROC bit

Re: [PATCH] n_tty: Remove LINEMODE support

2015-01-19 Thread Howard Chu
works. You'll have to use a dumb shell to see any effect. -- -- Howard Chu CTO, Symas Corp. http://www.symas.com Director, Highland Sun http://highlandsun.com/hyc/ Chief Architect, OpenLDAP http://www.openldap.org/project/ -- To unsubscribe from this list: send the line &q

Re: [PATCH] n_tty: Remove LINEMODE support

2015-01-19 Thread Howard Chu
Peter Hurley wrote: On 01/19/2015 11:36 AM, Howard Chu wrote: Peter Hurley wrote: Thanks, Howard. [ adding Ted too ] On 01/19/2015 07:46 AM, Howard Chu wrote: Peter Hurley wrote: On 01/18/2015 05:45 PM, Howard Chu wrote: Peter Hurley wrote: Commit 26df6d13406d1 ("tty: Add EXTPROC su

Re: [PATCH] n_tty: Remove LINEMODE support

2015-01-19 Thread Howard Chu
Peter Hurley wrote: Thanks, Howard. [ adding Ted too ] On 01/19/2015 07:46 AM, Howard Chu wrote: Peter Hurley wrote: On 01/18/2015 05:45 PM, Howard Chu wrote: Peter Hurley wrote: Commit 26df6d13406d1 ("tty: Add EXTPROC support for LINEMODE") added the undocumented EXTPROC input

Re: [PATCH] n_tty: Remove LINEMODE support

2015-01-19 Thread Howard Chu
Peter Hurley wrote: On 01/18/2015 05:45 PM, Howard Chu wrote: Peter Hurley wrote: Commit 26df6d13406d1 ("tty: Add EXTPROC support for LINEMODE") added the undocumented EXTPROC input processing mode, which ignores the ICANON setting and forces pty slave input to be processed in non

Re: [PATCH] n_tty: Remove LINEMODE support

2015-01-18 Thread Howard Chu
/pipermail/cryptography/2015-January/024288.html Cc: Howard Chu Signed-off-by: Peter Hurley --- drivers/tty/n_tty.c | 22 ++ drivers/tty/pty.c | 24 +--- 2 files changed, 7 insertions(+), 39 deletions(-) diff --git a/drivers/tty/n_tty.c b/drivers/t

Re: [PATCH] n_tty: Remove LINEMODE support

2015-01-18 Thread Howard Chu
Peter Hurley wrote: Hi Howard, On 01/18/2015 05:09 PM, Howard Chu wrote: Peter Hurley wrote: Commit 26df6d13406d1 ("tty: Add EXTPROC support for LINEMODE") added the undocumented EXTPROC input processing mode, which ignores the ICANON setting and forces pty slave input to be proces

Re: [PATCH v8 00/22] Support ext4 on NV-DIMMs

2014-07-23 Thread Howard Chu
Matthew Wilcox wrote: On Wed, Jul 23, 2014 at 07:10:32AM -0700, Howard Chu wrote: Matthew Wilcox wrote: One of the primary uses for NV-DIMMs is to expose them as a block device and use a filesystem to store files on the NV-DIMM. While that works, it currently wastes memory and CPU time

Re: [PATCH v8 00/22] Support ext4 on NV-DIMMs

2014-07-23 Thread Howard Chu
get persistence/safety for every filesystem mounted on a machine, not just a special case ext4. -- -- Howard Chu CTO, Symas Corp. http://www.symas.com Director, Highland Sun http://highlandsun.com/hyc/ Chief Architect, OpenLDAP http://www.openldap.org/project/ -- To

3.12.9 kern.log spam from vgaswitcheroo

2014-06-07 Thread Howard Chu
! Turning the discrete GPU back on stops the stream of messages. -- -- Howard Chu CTO, Symas Corp. http://www.symas.com Director, Highland Sun http://highlandsun.com/hyc/ Chief Architect, OpenLDAP http://www.openldap.org/project/ -- To unsubscribe from this list: send the line

Re: sched: RT throttling activated, 3.12.3

2013-12-10 Thread Howard Chu
Howard Chu wrote: Howard Chu wrote: Li Zefan wrote: On 2013/12/11 10:59, Howard Chu wrote: I just upgraded a system from a 3.5 kernel to 3.12.3 and attempted to run some new benchmarks on it. I see my test program ramps up in CPU usage for a few seconds and then it gradually tails off

Re: sched: RT throttling activated, 3.12.3

2013-12-10 Thread Howard Chu
Howard Chu wrote: Li Zefan wrote: On 2013/12/11 10:59, Howard Chu wrote: I just upgraded a system from a 3.5 kernel to 3.12.3 and attempted to run some new benchmarks on it. I see my test program ramps up in CPU usage for a few seconds and then it gradually tails off. There's nothing ob

Re: sched: RT throttling activated, 3.12.3

2013-12-10 Thread Howard Chu
Li Zefan wrote: On 2013/12/11 10:59, Howard Chu wrote: I just upgraded a system from a 3.5 kernel to 3.12.3 and attempted to run some new benchmarks on it. I see my test program ramps up in CPU usage for a few seconds and then it gradually tails off. There's nothing obvious in the user

sched: RT throttling activated, 3.12.3

2013-12-10 Thread Howard Chu
] perf samples too long (285964 > 142857), lowering kernel.perf_event_max_sample_rate to 1000 [208528.976208] perf samples too long (283799 > 25), lowering kernel.perf_event_max_sample_rate to 500 Why is the kernel throttling my server? -- -- Howard Chu CTO, Symas Corp. ht

Re: Why is O_DSYNC on linux so slow / what's wrong with my SSD?

2013-11-20 Thread Howard Chu
g a kill -9 on the VM, then you can resume the VM pretty quickly instead of waiting for a full reboot sequence. -- -- Howard Chu CTO, Symas Corp. http://www.symas.com Director, Highland Sun http://highlandsun.com/hyc/ Chief Architect, OpenLDAP http://www.openldap.org

Re: dirty_expire_centisecs, msync behavior

2013-09-10 Thread Howard Chu
Jan Kara wrote: Hello, Hi Jan, thanks for your answers. On Sat 07-09-13 17:01:10, Howard Chu wrote: The documentation for dirty_expire_centisecs states: "Data which has been dirty in-memory for longer than this interval will be written out next time a flusher thread wakes up.

dirty_expire_centisecs, msync behavior

2013-09-07 Thread Howard Chu
progress without any delay but that doesn't seem to be the case. -- -- Howard Chu CTO, Symas Corp. http://www.symas.com Director, Highland Sun http://highlandsun.com/hyc/ Chief Architect, OpenLDAP http://www.openldap.org/project/ -- To unsubscribe from this list: send

Re: mmap vs fs cache

2013-03-11 Thread Howard Chu
Jan Kara wrote: On Fri 08-03-13 12:04:46, Howard Chu wrote: The test clearly is accessing only 30GB of data. Once slapd reaches this process size, the test can be stopped and restarted any number of times, run for any number of hours continuously, and memory use on the system is unchanged, and

Re: mmap vs fs cache

2013-03-08 Thread Howard Chu
Johannes Weiner wrote: On Fri, Mar 08, 2013 at 07:00:55AM -0800, Howard Chu wrote: Chris Friesen wrote: On 03/08/2013 03:40 AM, Howard Chu wrote: There is no way that a process that is accessing only 30GB of a mmap should be able to fill up 32GB of RAM. There's nothing else running o

Re: mmap vs fs cache

2013-03-08 Thread Howard Chu
Chris Friesen wrote: On 03/08/2013 03:40 AM, Howard Chu wrote: There is no way that a process that is accessing only 30GB of a mmap should be able to fill up 32GB of RAM. There's nothing else running on the machine, I've killed or suspended everything else in userland besides a cou

Re: mmap vs fs cache

2013-03-08 Thread Howard Chu
Kirill A. Shutemov wrote: On Thu, Mar 07, 2013 at 11:46:39PM -0800, Howard Chu wrote: You're misreading the information then. slapd is doing no caching of its own, its RSS and SHR memory size are both the same. All it is using is the mmap, nothing else. The RSS == SHR == FS cache, up to

Re: mmap vs fs cache

2013-03-07 Thread Howard Chu
already tried setting it to 0 with no effect. -- -- Howard Chu CTO, Symas Corp. http://www.symas.com Director, Highland Sun http://highlandsun.com/hyc/ Chief Architect, OpenLDAP http://www.openldap.org/project/ -- To unsubscribe from this list: send the line "unsubscrib

Re: mmap vs fs cache

2013-03-06 Thread Howard Chu
Howard Chu wrote: Howard Chu wrote: Howard Chu wrote: 2 questions: why is there data in the FS cache that isn't owned by (the mmap of) the process that caused it to be paged in in the first place? is there a tunable knob to discourage the page cache from stealing from the pr

Re: mmap vs fs cache

2013-03-06 Thread Howard Chu
Howard Chu wrote: Howard Chu wrote: 2 questions: why is there data in the FS cache that isn't owned by (the mmap of) the process that caused it to be paged in in the first place? is there a tunable knob to discourage the page cache from stealing from the process? This Unmapped

Re: mmap vs fs cache

2013-03-05 Thread Howard Chu
Howard Chu wrote: 2 questions: why is there data in the FS cache that isn't owned by (the mmap of) the process that caused it to be paged in in the first place? is there a tunable knob to discourage the page cache from stealing from the process? This Unmapped page cache control

mmap vs fs cache

2013-03-05 Thread Howard Chu
7;t get there without a lot of babysitting. 2 questions: why is there data in the FS cache that isn't owned by (the mmap of) the process that caused it to be paged in in the first place? is there a tunable knob to discourage the page cache from stealing from the process? --

Re: [PATCH, 3.7-rc7, RESEND] fs: revert commit bbdd6808 to fallocate UAPI

2012-12-08 Thread Howard Chu
Dave Chinner wrote: On Fri, Dec 07, 2012 at 03:25:53PM -0800, Howard Chu wrote: I have to agree that, if this is going to be an ext4-specific feature, then it can just be implemented via an ext4-specific ioctl and be done with it. But I'm not convinced this should be an ext4-specific fe

Re: [PATCH, 3.7-rc7, RESEND] fs: revert commit bbdd6808 to fallocate UAPI

2012-12-07 Thread Howard Chu
known to belong to the same user, then the whole argument about "seeing someone else's data" is moot. If you provide the uid=/gid= mount options generically across all (or most) filesystem types, then you can let a sysadmin decide if they want to play this way or not. -- --

Re: [sqlite] light weight write barriers

2012-11-16 Thread Howard Chu
Ric Wheeler wrote: On 11/16/2012 10:06 AM, Howard Chu wrote: David Lang wrote: barriers keep getting mentioned because they are a easy concept to understand. "do this set of stuff before doing any of this other set of stuff, but I don't care when any of this gets done" and the

Re: [sqlite] light weight write barriers

2012-11-16 Thread Howard Chu
it. And in most cases it would be a zero-cost fix for them. Once you have drives that are actually trustworthy, actually reliable (which doesn't mean they never fail, it only means they tell the truth about successes or failures), most of these other issues disappear. Most of the need

Re: [sqlite] light weight write barriers

2012-11-01 Thread Howard Chu
filesystems and/or devices, so per-file control would be tedious. You would most likely want to say "all writes to this string of devices should be order-preserving" and forget about it. With that guarantee, a careful writer can have perfectly intact data structures all the time, witho

Re: MTRR initialization

2007-09-21 Thread Howard Chu
Siddha, Suresh B wrote: On Fri, Sep 14, 2007 at 09:33:30AM -0700, Howard Chu wrote: So now I have this, which is pretty much what I wanted: reg00: base=0x ( 0MB), size=2048MB: write-back, count=1 reg01: base=0x8000 (2048MB), size=1024MB: write-back, count=1 reg02: base

Re: MTRR initialization

2007-09-18 Thread Howard Chu
etup that the BIOS left me with, this is still a no-go. There's no way to get the desired effect without completely reinitializing the MTRRs. Of course, this isn't the only problem with these Asus BIOSs... -- -- Howard Chu Chief Architect, Symas Corp. http://www.symas.com Di

Re: MTRR initialization

2007-09-16 Thread Howard Chu
Yinghai Lu wrote: On 9/14/07, Howard Chu <[EMAIL PROTECTED]> wrote: Hi, was wondering if anyone else has been tripped up by this... I've got 4GB of RAM in my Asus A8V Deluxe and memory hole mapping enabled in the BIOS. By default, my system boots up with these MTRR settings:

MTRR initialization

2007-09-14 Thread Howard Chu
h I'm not sure that would have helped in this case. -- -- Howard Chu Chief Architect, Symas Corp. http://www.symas.com Director, Highland Sunhttp://highlandsun.com/hyc/ Chief Architect, OpenLDAP http://www.openldap.org/project/ - To unsubscribe from this list: send the

2.6.22.6 pata_via cable detect

2007-09-03 Thread Howard Chu
eneric sg6 type 5 Let me know what other info you need. -- -- Howard Chu Chief Architect, Symas Corp. http://www.symas.com Director, Highland Sunhttp://highlandsun.com/hyc/ Chief Architect, OpenLDAP http://www.openldap.org/project/ - To unsubscribe from this list: send the li

TCP 2MSL on loopback

2007-03-05 Thread Howard Chu
mall value; with any router hops use the large value. -- -- Howard Chu Chief Architect, Symas Corp. http://www.symas.com Director, Highland Sunhttp://highlandsun.com/hyc Chief Architect, OpenLDAP http://www.openldap.org/project/ - To unsubscribe from this list: send the line &q

swap map

2007-01-30 Thread Howard Chu
but I was thinking one could get a snapshot of that, correlated with traces from a malloc profiler, to show what portions of a program's memory usage was in active use vs idle. -- -- Howard Chu Chief Architect, Symas Corp. http://www.symas.com Director, Highland Sunhttp://highl

Re: Concurrent Page Cache

2007-01-30 Thread Howard Chu
cales better than just holding onto one lock or a small number of locks. -- -- Howard Chu Chief Architect, Symas Corp. http://www.symas.com Director, Highland Sunhttp://highlandsun.com/hyc OpenLDAP Core Teamhttp://www.openldap.org/project/ - To unsubscribe from this list:

Re: Why active list and inactive list?

2007-01-30 Thread Howard Chu
n a machine with only 2GB of free RAM. Walk through each memory range and make sure the balance of memory shifts as expected. Cycle that, increase the stride on each cycle, and toss some other variations in there. You don't need to drive real apps, you just need to have a couple of threads e

Re: Why active list and inactive list?

2007-01-30 Thread Howard Chu
the performance cost would come down.) -- -- Howard Chu Chief Architect, Symas Corp. http://www.symas.com Director, Highland Sunhttp://highlandsun.com/hyc OpenLDAP Core Teamhttp://www.openldap.org/project/ - To unsubscribe from this list: send the line "unsubscribe

re: skge error; hangs w/ hardware memory hole (was re: X86_64 + VIA + 4g problems)

2006-11-26 Thread Howard Chu
B, 3904MB are visible. With the aperture set to 256MB, the full 4096MB are visible. -- -- Howard Chu Chief Architect, Symas Corp. http://www.symas.com Director, Highland Sunhttp://highlandsun.com/hyc OpenLDAP Core Teamhttp://www.openldap.org/project/ - To unsubscribe fr

Re: 2.6, devfs, SMP, SATA

2005-09-05 Thread Howard Chu
Pekka Enberg wrote: On 9/5/05, Howard Chu <[EMAIL PROTECTED]> wrote: So, any guesses why with otherwise identical config options, a kernel with SMP enabled doesn't boot up with all of the device nodes that it should? (Both drives are on the same controller. I haven't check

2.6, devfs, SMP, SATA

2005-09-04 Thread Howard Chu
enabled doesn't boot up with all of the device nodes that it should? (Both drives are on the same controller. I haven't checked to see if any other device files are missing.) -- -- Howard Chu Chief Architect, Symas Corp. http://www.symas.com Director, Highland Sunh

Re: Very strange Marvell/Yukon Gigabit NIC networking problems

2005-09-01 Thread Howard Chu
into a "Soft Off" state, which is probably why the anomaly persists across a power off. You should also test if powering off and removing the power plug will allow booting to XP to work. -- -- Howard Chu Chief Architect, Symas Corp. http://www.symas.com Director, Highland Sun

Re: sched_yield() makes OpenLDAP slow

2005-08-22 Thread Howard Chu
Florian Weimer wrote: * Howard Chu: > That's not the complete story. BerkeleyDB provides a > db_env_set_func_yield() hook to tell it what yield function it > should use when its internal locking routines need such a function. > If you don't set a specific hook, it

Re: sched_yield() makes OpenLDAP slow

2005-08-22 Thread Howard Chu
ld functions to work in System scope. -- -- Howard Chu Chief Architect, Symas Corp. http://www.symas.com Director, Highland Sunhttp://highlandsun.com/hyc OpenLDAP Core Teamhttp://www.openldap.org/project/ - To unsubscribe from this list: send the line "unsubscribe linux

Re: sched_yield() makes OpenLDAP slow

2005-08-22 Thread Howard Chu
Nikita Danilov wrote: Howard Chu writes: > That's beside the point. Folks are making an assertion that > sched_yield() is meaningless; this example demonstrates that there are > cases where sched_yield() is essential. It is not essential, it is non-portable. Code you describ

Re: sched_yield() makes OpenLDAP slow

2005-08-22 Thread Howard Chu
ss if the end result isn't useful. Windows NT has a POSIX-compliant subsystem but it is utterly useless. That's what you wind up with when all you do is conform to the letter of the spec. -- -- Howard Chu Chief Architect, Symas Corp. http://www.symas.com Director, Highland Su

Re: sched_yield() makes OpenLDAP slow

2005-08-20 Thread Howard Chu
Lee Revell wrote: On Sat, 2005-08-20 at 11:38 -0700, Howard Chu wrote: > But I also found that I needed to add a new yield(), to work around > yet another unexpected issue on this system - we have a number of > threads waiting on a condition variable, and the thread holding the > m

Re: sched_yield() makes OpenLDAP slow

2005-08-20 Thread Howard Chu
thread (not process) to yield the processor. -- -- Howard Chu Chief Architect, Symas Corp. http://www.symas.com Director, Highland Sunhttp://highlandsun.com/hyc OpenLDAP Core Teamhttp://www.openldap.org/project/ - To unsubscribe from this list: send the line "unsubsc

Re: sched_yield() makes OpenLDAP slow

2005-08-20 Thread Howard Chu
eory, but reality says otherwise. To say that sched_yield is basically meaningless is far overstating your point. -- -- Howard Chu Chief Architect, Symas Corp. http://www.symas.com Director, Highland Sunhttp://highlandsun.com/hyc OpenLDAP Core Teamhttp://www.openldap.org

Re: sched_yield() makes OpenLDAP slow

2005-08-19 Thread Howard Chu
Nikita Danilov wrote: Howard Chu <[EMAIL PROTECTED]> writes: > concurrency. It is the nature of such a system to encounter > deadlocks over the normal course of operations. When a deadlock is > detected, some thread must be chosen (by one of a variety of > algorithms) to abo

Re: sched_yield() makes OpenLDAP slow

2005-08-19 Thread Howard Chu
Chris Wedgwood wrote: On Thu, Aug 18, 2005 at 11:03:45PM -0700, Howard Chu wrote: > If the 2.6 kernel makes this programming model unreasonably slow, > then quite simply this kernel is not viable as a database platform. Pretty much everyone else manages to make it work. An

Re: 2.6.12.3 network slowdown?

2005-07-27 Thread Howard Chu
Stephen Hemminger wrote: On Wed, 27 Jul 2005 01:44:43 -0700 Howard Chu <[EMAIL PROTECTED]> wrote: I just recently compiled the 2.6.12.3 kernel for my x86_64 machine (Asus A8V motherboard); was previously running a SuSE-compiled 2.6.8 kernel (SuSE 9.2 distro). I'm now seeing ext

2.6.12.3 network slowdown?

2005-07-27 Thread Howard Chu
cs, just a very slow transmit rate. Does anyone recognize this symptom? Any suggestions on tunables to tweak, etc.? (Please cc: me directly when replying, thanks.) -- -- Howard Chu Chief Architect, Symas Corp. http://www.symas.com Director, Highland Sunhttp://highlandsun.com/hyc