From patchwork Thu Apr 19 16:29:23 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anton Vorontsov X-Patchwork-Id: 7951 Return-Path: X-Original-To: patchwork@peony.canonical.com Delivered-To: patchwork@peony.canonical.com Received: from fiordland.canonical.com (fiordland.canonical.com [91.189.94.145]) by peony.canonical.com (Postfix) with ESMTP id D0B1223E20 for ; Thu, 19 Apr 2012 16:30:43 +0000 (UTC) Received: from mail-iy0-f180.google.com (mail-iy0-f180.google.com [209.85.210.180]) by fiordland.canonical.com (Postfix) with ESMTP id 76392A180CB for ; Thu, 19 Apr 2012 16:30:43 +0000 (UTC) Received: by iage36 with SMTP id e36so16574240iag.11 for ; Thu, 19 Apr 2012 09:30:43 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=x-forwarded-to:x-forwarded-for:delivered-to:received-spf:date:from :to:cc:subject:message-id:references:mime-version:content-type :content-disposition:in-reply-to:user-agent:x-gm-message-state; bh=42ELK+N5uP91LglSQBsJatuG8TEehmtq7m6Sa6yNdVM=; b=cxRFLL+EKau41hiID+adz0PurlE6YiLskRrMcEpMyDq74el58wEwnzWdt0SZpafCyb tFHwclO6ZksSKYiCKSNYpx9y3xS1TTDw570CV0JE1OtWVLeD7vGJVgLbRlQvK2tng8OG DFfaFr4tV3egnS6pLcNi6vYzVH5Sc81R/wn3XZpnefXUPtkXmDblvcMQo+Wv+3gGDRYB oDSLDwJTCT1yZ7cBofebpZlEKj+UHXoeaBJMLmiykFKOWUa+JTXRgMqW15gG9PoohSuI MPIvlPQy87zi3Vg62+nPdiYDKFf4iKPTa6+psuCAsqw6/E+Dcfe7BKHnm9le7r5WWZyW t43Q== Received: by 10.50.10.201 with SMTP id k9mr2994554igb.55.1334853042770; Thu, 19 Apr 2012 09:30:42 -0700 (PDT) X-Forwarded-To: linaro-patchwork@canonical.com X-Forwarded-For: patch@linaro.org linaro-patchwork@canonical.com Delivered-To: patches@linaro.org Received: by 10.231.137.198 with SMTP id x6csp302125ibt; Thu, 19 Apr 2012 09:30:41 -0700 (PDT) Received: by 10.236.181.36 with SMTP id k24mr2658045yhm.96.1334853040678; Thu, 19 Apr 2012 09:30:40 -0700 (PDT) Received: from mail-gy0-f178.google.com (mail-gy0-f178.google.com [209.85.160.178]) by mx.google.com with ESMTPS id q65si2770431yhm.42.2012.04.19.09.30.40 (version=TLSv1/SSLv3 cipher=OTHER); Thu, 19 Apr 2012 09:30:40 -0700 (PDT) Received-SPF: neutral (google.com: 209.85.160.178 is neither permitted nor denied by best guess record for domain of anton.vorontsov@linaro.org) client-ip=209.85.160.178; Authentication-Results: mx.google.com; spf=neutral (google.com: 209.85.160.178 is neither permitted nor denied by best guess record for domain of anton.vorontsov@linaro.org) smtp.mail=anton.vorontsov@linaro.org Received: by ghbf1 with SMTP id f1so5334603ghb.37 for ; Thu, 19 Apr 2012 09:30:40 -0700 (PDT) Received: by 10.60.28.103 with SMTP id a7mr3891309oeh.24.1334853039936; Thu, 19 Apr 2012 09:30:39 -0700 (PDT) Received: from localhost ([69.199.155.45]) by mx.google.com with ESMTPS id in4sm3197135obb.2.2012.04.19.09.30.36 (version=TLSv1/SSLv3 cipher=OTHER); Thu, 19 Apr 2012 09:30:38 -0700 (PDT) Date: Thu, 19 Apr 2012 09:29:23 -0700 From: Anton Vorontsov To: Pekka Enberg Cc: Leonid Moiseichuk , John Stultz , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linaro-kernel@lists.linaro.org, patches@linaro.org Subject: [PATCH v3 2/2] vmevent: Implement greater-than attribute and one-shot mode Message-ID: <20120419162923.GA26630@lizard> References: <20120418083208.GA24904@lizard> <20120418083523.GB31556@lizard> <20120418224629.GA22150@lizard> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-Gm-Message-State: ALoCoQmfJFlZFWFsytWvToMkdfa4GCp0m9CvgWEHFD+ByHRoTSqQ1oUiNSOUpB0mkmDHDtno3t8j This patch implements a new event type, it will trigger whenever a value becomes greater than user-specified threshold, it complements the 'less-then' trigger type. Also, let's implement the one-shot mode for the events, when set, userspace will only receive one notification per crossing the boundaries. Now when both LT and GT are set on the same level, the event type works as a cross event type: it triggers whenever a value crosses the threshold from a lesser values side to a greater values side, and vice versa. We use the event types in an userspace low-memory killer: we get a notification when memory becomes low, so we start freeing memory by killing unneeded processes, and we get notification when memory hits the threshold from another side, so we know that we freed enough of memory. Signed-off-by: Anton Vorontsov --- On Thu, Apr 19, 2012 at 08:42:14AM +0300, Pekka Enberg wrote: > On Wed, 18 Apr 2012, Anton Vorontsov wrote: > > Yep, with CONFIG_SWAP=n, and I had to a modify the test > > since I saw the same thing, I believe. I'll try w/ the swap enabled, > > and see how it goes. I think the vmevent-test.c needs some improvemnts > > in general, but meanwhile... > > > > > Physical pages: 109858 > > > read failed: Invalid argument > > > > Can you send me the .config file that you used? Might be that > > you have CONFIG_SWAP=n too? > > No, I have CONFIG_SWAP=y. Here's the config I use. Thanks! It appears that there was just another hard-coded value for the counter in vmevent-test.c, I changed it to config.counter and now everything should be fine. include/linux/vmevent.h | 13 ++++++++++ mm/vmevent.c | 44 +++++++++++++++++++++++++++++----- tools/testing/vmevent/vmevent-test.c | 24 ++++++++++++++----- 3 files changed, 69 insertions(+), 12 deletions(-) diff --git a/include/linux/vmevent.h b/include/linux/vmevent.h index 64357e4..ca97cf0 100644 --- a/include/linux/vmevent.h +++ b/include/linux/vmevent.h @@ -22,6 +22,19 @@ enum { * Sample value is less than user-specified value */ VMEVENT_ATTR_STATE_VALUE_LT = (1UL << 0), + /* + * Sample value is greater than user-specified value + */ + VMEVENT_ATTR_STATE_VALUE_GT = (1UL << 1), + /* + * One-shot mode. + */ + VMEVENT_ATTR_STATE_ONE_SHOT = (1UL << 2), + + /* Saved state, used internally by the kernel for one-shot mode. */ + __VMEVENT_ATTR_STATE_VALUE_WAS_LT = (1UL << 30), + /* Saved state, used internally by the kernel for one-shot mode. */ + __VMEVENT_ATTR_STATE_VALUE_WAS_GT = (1UL << 31), }; struct vmevent_attr { diff --git a/mm/vmevent.c b/mm/vmevent.c index 9ed6aca..3cce215 100644 --- a/mm/vmevent.c +++ b/mm/vmevent.c @@ -1,5 +1,6 @@ #include #include +#include #include #include #include @@ -83,16 +84,47 @@ static bool vmevent_match(struct vmevent_watch *watch) for (i = 0; i < config->counter; i++) { struct vmevent_attr *attr = &config->attrs[i]; - u64 value; + u32 state = attr->state; + bool attr_lt = state & VMEVENT_ATTR_STATE_VALUE_LT; + bool attr_gt = state & VMEVENT_ATTR_STATE_VALUE_GT; - if (!attr->state) + if (!state) continue; - value = vmevent_sample_attr(watch, attr); - - if (attr->state & VMEVENT_ATTR_STATE_VALUE_LT) { - if (value < attr->value) + if (attr_lt || attr_gt) { + bool one_shot = state & VMEVENT_ATTR_STATE_ONE_SHOT; + u32 was_lt_mask = __VMEVENT_ATTR_STATE_VALUE_WAS_LT; + u32 was_gt_mask = __VMEVENT_ATTR_STATE_VALUE_WAS_GT; + u64 value = vmevent_sample_attr(watch, attr); + bool lt = value < attr->value; + bool gt = value > attr->value; + bool was_lt = state & was_lt_mask; + bool was_gt = state & was_gt_mask; + bool ret = false; + + if ((lt || gt) && !one_shot) return true; + + if (attr_lt && lt && was_lt) { + return false; + } else if (attr_gt && gt && was_gt) { + return false; + } else if (lt) { + state |= was_lt_mask; + state &= ~was_gt_mask; + if (attr_lt) + ret = true; + } else if (gt) { + state |= was_gt_mask; + state &= ~was_lt_mask; + if (attr_gt) + ret = true; + } else { + state &= ~was_lt_mask; + state &= ~was_gt_mask; + } + attr->state = state; + return ret; } } diff --git a/tools/testing/vmevent/vmevent-test.c b/tools/testing/vmevent/vmevent-test.c index 534f827..fd9a174 100644 --- a/tools/testing/vmevent/vmevent-test.c +++ b/tools/testing/vmevent/vmevent-test.c @@ -33,20 +33,32 @@ int main(int argc, char *argv[]) config = (struct vmevent_config) { .sample_period_ns = 1000000000L, - .counter = 4, + .counter = 6, .attrs = { - [0] = { + { .type = VMEVENT_ATTR_NR_FREE_PAGES, .state = VMEVENT_ATTR_STATE_VALUE_LT, .value = phys_pages, }, - [1] = { + { + .type = VMEVENT_ATTR_NR_FREE_PAGES, + .state = VMEVENT_ATTR_STATE_VALUE_GT, + .value = phys_pages, + }, + { + .type = VMEVENT_ATTR_NR_FREE_PAGES, + .state = VMEVENT_ATTR_STATE_VALUE_LT | + VMEVENT_ATTR_STATE_VALUE_GT | + VMEVENT_ATTR_STATE_ONE_SHOT, + .value = phys_pages / 2, + }, + { .type = VMEVENT_ATTR_NR_AVAIL_PAGES, }, - [2] = { + { .type = VMEVENT_ATTR_NR_SWAP_PAGES, }, - [3] = { + { .type = 0xffff, /* invalid */ }, }, @@ -59,7 +71,7 @@ int main(int argc, char *argv[]) } for (i = 0; i < 10; i++) { - char buffer[sizeof(struct vmevent_event) + 4 * sizeof(struct vmevent_attr)]; + char buffer[sizeof(struct vmevent_event) + config.counter * sizeof(struct vmevent_attr)]; struct vmevent_event *event; int n = 0; int idx;