From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CD40AC433DF for ; Thu, 25 Jun 2020 11:32:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AA8D0207E8 for ; Thu, 25 Jun 2020 11:32:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="fOFHT436" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404355AbgFYLcF (ORCPT ); Thu, 25 Jun 2020 07:32:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47472 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404274AbgFYLcD (ORCPT ); Thu, 25 Jun 2020 07:32:03 -0400 Received: from casper.infradead.org (unknown [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C0233C061573; Thu, 25 Jun 2020 04:32:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=mFSG9oe6oASQv2j0OrxMcHvjeIF6oUGHMTMcMkcCnrM=; b=fOFHT4360Ni6vzSN6CHRl8qOUN SC+/ARqKz2mtW6UlT3JYoXonGt4ZrqId3cqJAw7Dso1Nh731SuantntDxFDkBFc4F2Db7rJWZ/RXn vRv/iBqYr4CeD86rVERzGCksxjKka0U0LS5t+f0TtaSlqvJSB8OMSs5WO67dPNSXWl7p0Wpsre4q1 gloJGO/sgYxcQ2Dt1axIVhfw+fRppDFUFRBEkw1jRFihwMSwNo4R1dG3AWqxVYPXHuTYVdLiM3WHX uFwoeqnq95Bv7UQXQEXf3KTQRysK1fjEaYq0sx4gctVgcxSKSS4U2F7kxjQjYkv00XZSL/xlAUz5H zey0QKGQ==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1joQ6W-0001zO-Ks; Thu, 25 Jun 2020 11:31:40 +0000 From: "Matthew Wilcox (Oracle)" To: linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: "Matthew Wilcox (Oracle)" , linux-xfs@vger.kernel.org, dm-devel@redhat.com, Mikulas Patocka , Jens Axboe , NeilBrown Subject: [PATCH 1/6] mm: Replace PF_MEMALLOC_NOIO with memalloc_noio Date: Thu, 25 Jun 2020 12:31:17 +0100 Message-Id: <20200625113122.7540-2-willy@infradead.org> X-Mailer: git-send-email 2.21.3 In-Reply-To: <20200625113122.7540-1-willy@infradead.org> References: <20200625113122.7540-1-willy@infradead.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org We're short on PF_* flags, so make memalloc_noio its own bit where we have plenty of space. Signed-off-by: Matthew Wilcox (Oracle) --- drivers/block/loop.c | 3 ++- drivers/md/dm-zoned-metadata.c | 5 ++--- include/linux/sched.h | 2 +- include/linux/sched/mm.h | 30 +++++++++++++++++++++++------- kernel/sys.c | 8 +++----- 5 files changed, 31 insertions(+), 17 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 475e1a738560..c8742e25e58a 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -52,6 +52,7 @@ #include #include #include +#include #include #include #include @@ -929,7 +930,7 @@ static void loop_unprepare_queue(struct loop_device *lo) static int loop_kthread_worker_fn(void *worker_ptr) { - current->flags |= PF_LOCAL_THROTTLE | PF_MEMALLOC_NOIO; + set_current_io_flusher(); return kthread_worker_fn(worker_ptr); } diff --git a/drivers/md/dm-zoned-metadata.c b/drivers/md/dm-zoned-metadata.c index 130b5a6d9f12..1c5ae674ba20 100644 --- a/drivers/md/dm-zoned-metadata.c +++ b/drivers/md/dm-zoned-metadata.c @@ -1599,9 +1599,8 @@ static int dmz_update_zone(struct dmz_metadata *zmd, struct dm_zone *zone) /* * Get zone information from disk. Since blkdev_report_zones() uses - * GFP_KERNEL by default for memory allocations, set the per-task - * PF_MEMALLOC_NOIO flag so that all allocations are done as if - * GFP_NOIO was specified. + * GFP_KERNEL by default for memory allocations, use + * memalloc_noio_save() to prevent recursion into the driver. */ noio_flag = memalloc_noio_save(); ret = blkdev_report_zones(dev->bdev, dmz_start_sect(zmd, zone), 1, diff --git a/include/linux/sched.h b/include/linux/sched.h index b62e6aaf28f0..cf18a3d2bc4c 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -801,6 +801,7 @@ struct task_struct { /* Stalled due to lack of memory */ unsigned in_memstall:1; #endif + unsigned memalloc_noio:1; unsigned long atomic_flags; /* Flags requiring atomic access. */ @@ -1505,7 +1506,6 @@ extern struct pid *cad_pid; #define PF_FROZEN 0x00010000 /* Frozen for system suspend */ #define PF_KSWAPD 0x00020000 /* I am kswapd */ #define PF_MEMALLOC_NOFS 0x00040000 /* All allocation requests will inherit GFP_NOFS */ -#define PF_MEMALLOC_NOIO 0x00080000 /* All allocation requests will inherit GFP_NOIO */ #define PF_LOCAL_THROTTLE 0x00100000 /* Throttle writes only against the bdi I write to, * I am cleaning dirty pages from some other bdi. */ #define PF_KTHREAD 0x00200000 /* I am a kernel thread */ diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h index 480a4d1b7dd8..1a7e1ab1be85 100644 --- a/include/linux/sched/mm.h +++ b/include/linux/sched/mm.h @@ -175,19 +175,18 @@ static inline bool in_vfork(struct task_struct *tsk) /* * Applies per-task gfp context to the given allocation flags. - * PF_MEMALLOC_NOIO implies GFP_NOIO * PF_MEMALLOC_NOFS implies GFP_NOFS * PF_MEMALLOC_NOCMA implies no allocation from CMA region. */ static inline gfp_t current_gfp_context(gfp_t flags) { - if (unlikely(current->flags & - (PF_MEMALLOC_NOIO | PF_MEMALLOC_NOFS | PF_MEMALLOC_NOCMA))) { + if (unlikely(current->flags & (PF_MEMALLOC_NOFS | PF_MEMALLOC_NOCMA) || + current->memalloc_noio)) { /* * NOIO implies both NOIO and NOFS and it is a weaker context * so always make sure it makes precedence */ - if (current->flags & PF_MEMALLOC_NOIO) + if (current->memalloc_noio) flags &= ~(__GFP_IO | __GFP_FS); else if (current->flags & PF_MEMALLOC_NOFS) flags &= ~__GFP_FS; @@ -224,8 +223,8 @@ static inline void fs_reclaim_release(gfp_t gfp_mask) { } */ static inline unsigned int memalloc_noio_save(void) { - unsigned int flags = current->flags & PF_MEMALLOC_NOIO; - current->flags |= PF_MEMALLOC_NOIO; + unsigned int flags = current->memalloc_noio; + current->memalloc_noio = 1; return flags; } @@ -239,7 +238,7 @@ static inline unsigned int memalloc_noio_save(void) */ static inline void memalloc_noio_restore(unsigned int flags) { - current->flags = (current->flags & ~PF_MEMALLOC_NOIO) | flags; + current->memalloc_noio = flags ? 1 : 0; } /** @@ -309,6 +308,23 @@ static inline void memalloc_nocma_restore(unsigned int flags) } #endif +static inline void set_current_io_flusher(void) +{ + current->flags |= PF_LOCAL_THROTTLE; + current->memalloc_noio = 1; +} + +static inline void clear_current_io_flusher(void) +{ + current->flags &= ~PF_LOCAL_THROTTLE; + current->memalloc_noio = 0; +} + +static inline bool get_current_io_flusher(void) +{ + return current->flags & PF_LOCAL_THROTTLE; +} + #ifdef CONFIG_MEMCG /** * memalloc_use_memcg - Starts the remote memcg charging scope. diff --git a/kernel/sys.c b/kernel/sys.c index 00a96746e28a..78c90d1e92f4 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -2275,8 +2275,6 @@ int __weak arch_prctl_spec_ctrl_set(struct task_struct *t, unsigned long which, return -EINVAL; } -#define PR_IO_FLUSHER (PF_MEMALLOC_NOIO | PF_LOCAL_THROTTLE) - SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, unsigned long, arg4, unsigned long, arg5) { @@ -2512,9 +2510,9 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, return -EINVAL; if (arg2 == 1) - current->flags |= PR_IO_FLUSHER; + set_current_io_flusher(); else if (!arg2) - current->flags &= ~PR_IO_FLUSHER; + clear_current_io_flusher(); else return -EINVAL; break; @@ -2525,7 +2523,7 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, if (arg2 || arg3 || arg4 || arg5) return -EINVAL; - error = (current->flags & PR_IO_FLUSHER) == PR_IO_FLUSHER; + error = get_current_io_flusher(); break; default: error = -EINVAL; -- 2.27.0