From: Ingo Molnar <mingo@elte.hu>
To: Andrew Morton <akpm@osdl.org>
Cc: linux-kernel@vger.kernel.org, Alan Cox <alan@lxorguk.ukuu.org.uk>
Subject: Re: [patch] sched: fix scheduling latencies in mtrr.c
Date: Tue, 14 Sep 2004 15:25:36 +0200 [thread overview]
Message-ID: <20040914132536.GA9742@elte.hu> (raw)
In-Reply-To: <20040914112847.GA2804@elte.hu>
[-- Attachment #1: Type: text/plain, Size: 318 bytes --]
> fix scheduling latencies in the MTRR-setting codepath.
> Also, fix bad bug: MTRR's _must_ be set with interrupts disabled!
patch attached ...
caveat: one of the wbinvd() removals is correct i believe, but the other
one might be problematic. It doesnt seem logical to do a wbinvd() at
that point though ...
Ingo
[-- Attachment #2: fix-latency-mtrr.patch --]
[-- Type: text/plain, Size: 1392 bytes --]
fix scheduling latencies in the MTRR-setting codepath.
Also, fix bad bug: MTRR's _must_ be set with interrupts disabled!
Signed-off-by: Ingo Molnar <mingo@elte.hu>
--- linux/arch/i386/kernel/cpu/mtrr/generic.c.orig
+++ linux/arch/i386/kernel/cpu/mtrr/generic.c
@@ -240,11 +240,14 @@ static void prepare_set(void)
/* Note that this is not ideal, since the cache is only flushed/disabled
for this CPU while the MTRRs are changed, but changing this requires
more invasive changes to the way the kernel boots */
- spin_lock(&set_atomicity_lock);
+ /*
+ * Since we are disabling the cache dont allow any interrupts - they
+ * would run extremely slow and would only increase the pain:
+ */
+ spin_lock_irq(&set_atomicity_lock);
/* Enter the no-fill (CD=1, NW=0) cache mode and flush caches. */
cr0 = read_cr0() | 0x40000000; /* set CD flag */
- wbinvd();
write_cr0(cr0);
wbinvd();
@@ -266,8 +269,7 @@ static void prepare_set(void)
static void post_set(void)
{
- /* Flush caches and TLBs */
- wbinvd();
+ /* Flush TLBs (no need to flush caches - they are disabled) */
__flush_tlb();
/* Intel (P6) standard MTRRs */
@@ -279,7 +281,7 @@ static void post_set(void)
/* Restore value of CR4 */
if ( cpu_has_pge )
write_cr4(cr4);
- spin_unlock(&set_atomicity_lock);
+ spin_unlock_irq(&set_atomicity_lock);
}
static void generic_set_all(void)
next prev parent reply other threads:[~2004-09-14 13:30 UTC|newest]
Thread overview: 76+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-09-14 9:15 [patch] preempt-cleanup.patch, 2.6.9-rc2 Ingo Molnar
2004-09-14 9:34 ` [printk] make console_conditional_schedule() __sched and use cond_resched() William Lee Irwin III
2004-09-14 9:38 ` [patch] preempt-lock-need-resched.patch, 2.6.9-rc2 Ingo Molnar
2004-09-14 9:51 ` [patch] sched: add cond_resched_softirq() Ingo Molnar
2004-09-14 9:57 ` [patch] sched: fix latency in random driver Ingo Molnar
2004-09-14 10:06 ` [patch] sched, ext3: fix scheduling latencies in ext3 Ingo Molnar
2004-09-14 10:13 ` [patch] sched, vfs: fix scheduling latencies in invalidate_inodes() Ingo Molnar
2004-09-14 10:19 ` [patch] sched, vfs: fix scheduling latencies in prune_dcache() and select_parent() Ingo Molnar
2004-09-14 10:25 ` [patch] sched, net: fix scheduling latencies in netstat Ingo Molnar
2004-09-14 10:44 ` [patch] sched, net: fix scheduling latencies in __release_sock Ingo Molnar
2004-09-14 10:50 ` [patch] sched, mm: fix scheduling latencies in copy_page_range() Ingo Molnar
2004-09-14 10:56 ` [patch] sched, mm: fix scheduling latencies in unmap_vmas() Ingo Molnar
2004-09-14 10:59 ` [patch] sched, mm: fix scheduling latencies in get_user_pages() Ingo Molnar
2004-09-14 11:02 ` [patch] sched, mm: fix scheduling latencies in filemap_sync() Ingo Molnar
2004-09-14 11:06 ` [patch] sched, tty: fix scheduling latencies in tty_io.c Ingo Molnar
2004-09-14 10:53 ` Alan Cox
2004-09-14 12:00 ` Ingo Molnar
2004-09-14 11:18 ` Alan Cox
2004-09-14 12:27 ` Ingo Molnar
2004-09-14 12:11 ` Alan Cox
2004-09-14 11:08 ` [patch] sched, pty: fix scheduling latencies in pty.c Ingo Molnar
2004-09-14 11:12 ` [patch] might_sleep() additions to fs-writeback.c Ingo Molnar
2004-09-14 11:25 ` [patch] fix keventd execution dependency Ingo Molnar
2004-09-15 22:18 ` Rusty Russell
2004-09-14 11:28 ` [patch] sched: fix scheduling latencies in mttr.c Ingo Molnar
2004-09-14 11:32 ` [patch] sched: fix scheduling latencies in vgacon.c Ingo Molnar
2004-09-14 11:35 ` [patch] sched: fix scheduling latencies in NTFS mount Ingo Molnar
2004-09-14 13:31 ` Anton Altaparmakov
2004-09-14 11:42 ` [patch] sched: fix scheduling latencies for !PREEMPT kernels Ingo Molnar
2004-09-14 12:55 ` Nick Piggin
2004-09-14 13:22 ` Ingo Molnar
2004-09-14 13:33 ` Nick Piggin
2004-09-14 14:09 ` Andrea Arcangeli
2004-09-14 14:28 ` Nick Piggin
2004-09-14 15:03 ` Andrea Arcangeli
2004-09-14 18:05 ` Robert Love
2004-09-14 18:52 ` William Lee Irwin III
2004-09-14 19:02 ` Robert Love
2004-09-14 19:21 ` William Lee Irwin III
2004-09-14 19:19 ` Alan Cox
2004-09-15 0:22 ` Lee Revell
2004-09-15 1:46 ` William Lee Irwin III
2004-09-15 2:00 ` Lee Revell
2004-09-15 2:36 ` William Lee Irwin III
2004-09-15 2:59 ` Lee Revell
2004-09-15 13:36 ` Hans Reiser
2004-09-15 20:40 ` William Lee Irwin III
2004-09-15 1:18 ` William Lee Irwin III
2004-09-14 19:26 ` Robert Love
2004-09-14 21:06 ` William Lee Irwin III
2004-09-14 19:25 ` Andrea Arcangeli
2004-09-14 19:29 ` Robert Love
2004-09-14 19:34 ` William Lee Irwin III
2004-09-15 1:02 ` Lee Revell
2004-09-15 1:39 ` William Lee Irwin III
2004-09-15 2:11 ` Lee Revell
2004-09-15 11:17 ` Ingo Molnar
2004-09-15 9:56 ` Ingo Molnar
2004-09-15 9:57 ` William Lee Irwin III
2004-09-15 10:12 ` Ingo Molnar
2004-09-14 16:31 ` William Lee Irwin III
2004-09-14 16:39 ` Andrea Arcangeli
2004-09-14 14:54 ` Ingo Molnar
2004-09-14 22:55 ` Nick Piggin
2004-09-15 6:19 ` Ingo Molnar
2004-09-15 8:23 ` Nick Piggin
2004-09-15 8:43 ` Ingo Molnar
2004-09-15 10:09 ` William Lee Irwin III
2004-09-15 10:21 ` Ingo Molnar
2004-09-16 1:03 ` Nick Piggin
2004-09-16 6:14 ` Ingo Molnar
2004-09-15 0:35 ` Lee Revell
2004-09-14 13:25 ` Ingo Molnar [this message]
2004-09-14 13:15 ` [patch] sched: fix scheduling latencies in mtrr.c Alan Cox
2004-09-14 15:00 ` Ingo Molnar
2004-09-14 18:22 ` Zwane Mwaikambo
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