From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932404Ab0KCPbD (ORCPT ); Wed, 3 Nov 2010 11:31:03 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34135 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932334Ab0KCPau (ORCPT ); Wed, 3 Nov 2010 11:30:50 -0400 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [PATCH 60 of 66] freeze khugepaged and ksmd X-Mercurial-Node: 99438562b17e61f5bf56480edfa8d406639efac0 Message-Id: <99438562b17e61f5bf56.1288798115@v2.random> In-Reply-To: References: User-Agent: Mercurial-patchbomb/1.4.1 Date: Wed, 03 Nov 2010 16:28:35 +0100 From: Andrea Arcangeli To: linux-mm@kvack.org, Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org Cc: Marcelo Tosatti , Adam Litke , Avi Kivity , Hugh Dickins , Rik van Riel , Mel Gorman , Dave Hansen , Benjamin Herrenschmidt , Ingo Molnar , Mike Travis , KAMEZAWA Hiroyuki , Christoph Lameter , Chris Wright , bpicco@redhat.com, KOSAKI Motohiro , Balbir Singh , "Michael S. Tsirkin" , Peter Zijlstra , Johannes Weiner , Daisuke Nishimura , Chris Mason , Borislav Petkov Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Andrea Arcangeli It's unclear why schedule friendly kernel threads can't be taken away by the CPU through the scheduler itself. It's safer to stop them as they can trigger memory allocation, if kswapd also freezes itself to avoid generating I/O they have too. Signed-off-by: Andrea Arcangeli --- diff --git a/mm/huge_memory.c b/mm/huge_memory.c --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include "internal.h" @@ -2063,6 +2064,9 @@ static void khugepaged_do_scan(struct pa break; #endif + if (unlikely(kthread_should_stop() || freezing(current))) + break; + spin_lock(&khugepaged_mm_lock); if (!khugepaged_scan.mm_slot) pass_through_head++; @@ -2125,6 +2129,9 @@ static void khugepaged_loop(void) if (hpage) put_page(hpage); #endif + try_to_freeze(); + if (unlikely(kthread_should_stop())) + break; if (khugepaged_has_work()) { DEFINE_WAIT(wait); if (!khugepaged_scan_sleep_millisecs) @@ -2135,8 +2142,8 @@ static void khugepaged_loop(void) khugepaged_scan_sleep_millisecs)); remove_wait_queue(&khugepaged_wait, &wait); } else if (khugepaged_enabled()) - wait_event_interruptible(khugepaged_wait, - khugepaged_wait_event()); + wait_event_freezable(khugepaged_wait, + khugepaged_wait_event()); } } @@ -2144,6 +2151,7 @@ static int khugepaged(void *none) { struct mm_slot *mm_slot; + set_freezable(); set_user_nice(current, 19); /* serialize with start_khugepaged() */ @@ -2158,6 +2166,8 @@ static int khugepaged(void *none) mutex_lock(&khugepaged_mutex); if (!khugepaged_enabled()) break; + if (unlikely(kthread_should_stop())) + break; } spin_lock(&khugepaged_mm_lock); diff --git a/mm/ksm.c b/mm/ksm.c --- a/mm/ksm.c +++ b/mm/ksm.c @@ -34,6 +34,7 @@ #include #include #include +#include #include #include "internal.h" @@ -1374,7 +1375,7 @@ static void ksm_do_scan(unsigned int sca struct rmap_item *rmap_item; struct page *uninitialized_var(page); - while (scan_npages--) { + while (scan_npages-- && likely(!freezing(current))) { cond_resched(); rmap_item = scan_get_next_rmap_item(&page); if (!rmap_item) @@ -1392,6 +1393,7 @@ static int ksmd_should_run(void) static int ksm_scan_thread(void *nothing) { + set_freezable(); set_user_nice(current, 5); while (!kthread_should_stop()) { @@ -1400,11 +1402,13 @@ static int ksm_scan_thread(void *nothing ksm_do_scan(ksm_thread_pages_to_scan); mutex_unlock(&ksm_thread_mutex); + try_to_freeze(); + if (ksmd_should_run()) { schedule_timeout_interruptible( msecs_to_jiffies(ksm_thread_sleep_millisecs)); } else { - wait_event_interruptible(ksm_thread_wait, + wait_event_freezable(ksm_thread_wait, ksmd_should_run() || kthread_should_stop()); } } From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with SMTP id E7B9D6B00BE for ; Wed, 3 Nov 2010 11:30:37 -0400 (EDT) Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [PATCH 60 of 66] freeze khugepaged and ksmd Message-Id: <99438562b17e61f5bf56.1288798115@v2.random> In-Reply-To: References: Date: Wed, 03 Nov 2010 16:28:35 +0100 From: Andrea Arcangeli Sender: owner-linux-mm@kvack.org To: linux-mm@kvack.org, Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org Cc: Marcelo Tosatti , Adam Litke , Avi Kivity , Hugh Dickins , Rik van Riel , Mel Gorman , Dave Hansen , Benjamin Herrenschmidt , Ingo Molnar , Mike Travis , KAMEZAWA Hiroyuki , Christoph Lameter , Chris Wright , bpicco@redhat.com, KOSAKI Motohiro , Balbir Singh , "Michael S. Tsirkin" , Peter Zijlstra , Johannes Weiner , Daisuke Nishimura , Chris Mason , Borislav Petkov List-ID: From: Andrea Arcangeli It's unclear why schedule friendly kernel threads can't be taken away by the CPU through the scheduler itself. It's safer to stop them as they can trigger memory allocation, if kswapd also freezes itself to avoid generating I/O they have too. Signed-off-by: Andrea Arcangeli --- diff --git a/mm/huge_memory.c b/mm/huge_memory.c --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include "internal.h" @@ -2063,6 +2064,9 @@ static void khugepaged_do_scan(struct pa break; #endif + if (unlikely(kthread_should_stop() || freezing(current))) + break; + spin_lock(&khugepaged_mm_lock); if (!khugepaged_scan.mm_slot) pass_through_head++; @@ -2125,6 +2129,9 @@ static void khugepaged_loop(void) if (hpage) put_page(hpage); #endif + try_to_freeze(); + if (unlikely(kthread_should_stop())) + break; if (khugepaged_has_work()) { DEFINE_WAIT(wait); if (!khugepaged_scan_sleep_millisecs) @@ -2135,8 +2142,8 @@ static void khugepaged_loop(void) khugepaged_scan_sleep_millisecs)); remove_wait_queue(&khugepaged_wait, &wait); } else if (khugepaged_enabled()) - wait_event_interruptible(khugepaged_wait, - khugepaged_wait_event()); + wait_event_freezable(khugepaged_wait, + khugepaged_wait_event()); } } @@ -2144,6 +2151,7 @@ static int khugepaged(void *none) { struct mm_slot *mm_slot; + set_freezable(); set_user_nice(current, 19); /* serialize with start_khugepaged() */ @@ -2158,6 +2166,8 @@ static int khugepaged(void *none) mutex_lock(&khugepaged_mutex); if (!khugepaged_enabled()) break; + if (unlikely(kthread_should_stop())) + break; } spin_lock(&khugepaged_mm_lock); diff --git a/mm/ksm.c b/mm/ksm.c --- a/mm/ksm.c +++ b/mm/ksm.c @@ -34,6 +34,7 @@ #include #include #include +#include #include #include "internal.h" @@ -1374,7 +1375,7 @@ static void ksm_do_scan(unsigned int sca struct rmap_item *rmap_item; struct page *uninitialized_var(page); - while (scan_npages--) { + while (scan_npages-- && likely(!freezing(current))) { cond_resched(); rmap_item = scan_get_next_rmap_item(&page); if (!rmap_item) @@ -1392,6 +1393,7 @@ static int ksmd_should_run(void) static int ksm_scan_thread(void *nothing) { + set_freezable(); set_user_nice(current, 5); while (!kthread_should_stop()) { @@ -1400,11 +1402,13 @@ static int ksm_scan_thread(void *nothing ksm_do_scan(ksm_thread_pages_to_scan); mutex_unlock(&ksm_thread_mutex); + try_to_freeze(); + if (ksmd_should_run()) { schedule_timeout_interruptible( msecs_to_jiffies(ksm_thread_sleep_millisecs)); } else { - wait_event_interruptible(ksm_thread_wait, + wait_event_freezable(ksm_thread_wait, ksmd_should_run() || kthread_should_stop()); } } -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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