Re: [PATCH 0/2] convert mmap_sem to a scalable rw_mutex

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

To: Peter Zijlstra <[email protected]>
Subject: Re: [PATCH 0/2] convert mmap_sem to a scalable rw_mutex
From: Esben Nielsen <[email protected]>
Date: Sat, 12 May 2007 11:27:13 +0200 (CEST)
Cc: [email protected], [email protected], Oleg Nesterov <[email protected]>, Andrew Morton <[email protected]>, Ingo Molnar <[email protected]>, Thomas Gleixner <[email protected]>, Nick Piggin <[email protected]>
In-reply-to: <[email protected]>
References: <[email protected]>
Sender: [email protected]



On Fri, 11 May 2007, Peter Zijlstra wrote:


I was toying with a scalable rw_mutex and found that it gives ~10% reduction in
system time on ebizzy runs (without the MADV_FREE patch).


You break priority enheritance on user space futexes! :-(

The problems is that the futex waiter have to take the mmap_sem. And asyour rw_mutex isn't PI enabled you get priority inversions :-(


Esben
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Follow-Ups:
- Re: [PATCH 0/2] convert mmap_sem to a scalable rw_mutex
  - From: Peter Zijlstra <[email protected]>

References:
- [PATCH 0/2] convert mmap_sem to a scalable rw_mutex
  - From: Peter Zijlstra <[email protected]>

Prev by Date: Re: [PATCH 1/7] Freezer: Read PF_BORROWED_MM in a nonracy way
Next by Date: Re: [PATCH 0/2] convert mmap_sem to a scalable rw_mutex
Previous by thread: Re: [PATCH 0/2] convert mmap_sem to a scalable rw_mutex
Next by thread: Re: [PATCH 0/2] convert mmap_sem to a scalable rw_mutex
Index(es):
- Date
- Thread

[Index of Archives] [Kernel Newbies] [Netfilter] [Bugtraq] [Photo] [Stuff] [Gimp] [Yosemite News] [MIPS Linux] [ARM Linux] [Linux Security] [Linux RAID] [Video 4 Linux] [Linux for the blind] [Linux Resources]

Powered by Linux