Messages in this thread | | | Subject | Re: vmalloc - kmalloc and page locks | Date | Tue, 22 Jul 2003 06:57:26 -0700 | From | "Deas, Jim" <> |
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Thanks for the clarification. I am using mlockall on the user application. This still leaves me with the mystery of why my system usage goes from 3% to 50% randomly while playing data streams off the harddrive. I can also make system usage stay at 50% by opening a third stream. These streams are pulling data at 1.5MB/s each from different files (same HD). I don't see that as a big strain on the hardware (4.5MB/s total data rate). Where else should I look to find the bottleneck/latency issue?
Regards, J. Deas
-----Original Message----- From: Gábor Lénárt [mailto:lgb@lgb.hu] Sent: Tuesday, July 22, 2003 6:13 AM To: Deas, Jim Cc: linux-kernel@vger.kernel.org Subject: Re: vmalloc - kmalloc and page locks
Errrrr ... Sorry, I did not read your mail carefully ;-( I meant in case of a user process you can use mlock() and such :) AFAIK the kernel itself is not pagable ...
On Tue, Jul 22, 2003 at 03:07:18PM +0200, Gábor Lénárt wrote: > Please read something about the mlock() and/or mlockall() functions. > The prototype can be found in [/usr/include/]sys/mman.h > You can read there: > > /* Guarantee all whole pages mapped by the range [ADDR,ADDR+LEN) to > be memory resident. */ > extern int mlock (__const void *__addr, size_t __len) __THROW; > [...] > /* Cause all currently mapped pages of the process to be memory resident > until unlocked by a call to the `munlockall', until the process exits, > or until the process calls `execve'. */ > extern int mlockall (int __flags) __THROW; > > On Tue, Jul 22, 2003 at 06:00:14AM -0700, Deas, Jim wrote: > > How can I look at what memory are being paged out of memory in the kernel > > or how to lock kmalloc and vmalloc pages so they do not get put to swap? > [...] > > - Gábor (larta'H) > - > 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/
-- - Gábor (larta'H)
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