From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Gabriel Krisman Bertazi <krisman@collabora.com>,
Tejun Heo <tj@kernel.org>, Jens Axboe <axboe@kernel.dk>,
Sasha Levin <sashal@kernel.org>,
cgroups@vger.kernel.org, linux-block@vger.kernel.org
Subject: [PATCH AUTOSEL 5.9 17/35] blk-cgroup: Pre-allocate tree node on blkg_conf_prep
Date: Mon, 2 Nov 2020 20:18:22 -0500 [thread overview]
Message-ID: <20201103011840.182814-17-sashal@kernel.org> (raw)
In-Reply-To: <20201103011840.182814-1-sashal@kernel.org>
From: Gabriel Krisman Bertazi <krisman@collabora.com>
[ Upstream commit f255c19b3ab46d3cad3b1b2e1036f4c926cb1d0c ]
Similarly to commit 457e490f2b741 ("blkcg: allocate struct blkcg_gq
outside request queue spinlock"), blkg_create can also trigger
occasional -ENOMEM failures at the radix insertion because any
allocation inside blkg_create has to be non-blocking, making it more
likely to fail. This causes trouble for userspace tools trying to
configure io weights who need to deal with this condition.
This patch reduces the occurrence of -ENOMEMs on this path by preloading
the radix tree element on a GFP_KERNEL context, such that we guarantee
the later non-blocking insertion won't fail.
A similar solution exists in blkcg_init_queue for the same situation.
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
block/blk-cgroup.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 7b2df042220d4..c85fbb666e40a 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -648,6 +648,12 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
goto fail;
}
+ if (radix_tree_preload(GFP_KERNEL)) {
+ blkg_free(new_blkg);
+ ret = -ENOMEM;
+ goto fail;
+ }
+
rcu_read_lock();
spin_lock_irq(&q->queue_lock);
@@ -655,7 +661,7 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
if (IS_ERR(blkg)) {
ret = PTR_ERR(blkg);
blkg_free(new_blkg);
- goto fail_unlock;
+ goto fail_preloaded;
}
if (blkg) {
@@ -664,10 +670,12 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
blkg = blkg_create(pos, q, new_blkg);
if (IS_ERR(blkg)) {
ret = PTR_ERR(blkg);
- goto fail_unlock;
+ goto fail_preloaded;
}
}
+ radix_tree_preload_end();
+
if (pos == blkcg)
goto success;
}
@@ -677,6 +685,8 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
ctx->body = input;
return 0;
+fail_preloaded:
+ radix_tree_preload_end();
fail_unlock:
spin_unlock_irq(&q->queue_lock);
rcu_read_unlock();
--
2.27.0
next prev parent reply other threads:[~2020-11-03 1:19 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-03 1:18 [PATCH AUTOSEL 5.9 01/35] ARM: dts: sun4i-a10: fix cpu_alert temperature Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 02/35] arm64: dts: meson-axg: add USB nodes Sasha Levin
2020-11-03 8:55 ` Neil Armstrong
2020-11-08 13:14 ` Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 03/35] arm64: dts: meson-axg-s400: enable USB OTG Sasha Levin
2020-11-03 8:55 ` Neil Armstrong
2020-11-08 13:14 ` Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 04/35] arm64: dts: meson: add missing g12 rng clock Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 05/35] arm64: dts: amlogic: meson-g12: use the G12A specific dwmac compatible Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 06/35] x86/kexec: Use up-to-dated screen_info copy to fill boot params Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 07/35] hyperv_fb: Update screen_info after removing old framebuffer Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 08/35] arm64: dts: amlogic: add missing ethernet reset ID Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 09/35] io_uring: don't miss setting IO_WQ_WORK_CONCURRENT Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 10/35] of: Fix reserved-memory overlap detection Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 11/35] ARM: dts: mmp3: Add power domain for the camera Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 12/35] drm/sun4i: frontend: Rework a bit the phase data Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 13/35] drm/sun4i: frontend: Reuse the ch0 phase for RGB formats Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 14/35] drm/sun4i: frontend: Fix the scaler phase on A33 Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 15/35] drm/v3d: Fix double free in v3d_submit_cl_ioctl() Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 16/35] blk-cgroup: Fix memleak on error path Sasha Levin
2020-11-03 1:18 ` Sasha Levin [this message]
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 18/35] btrfs: drop the path before adding qgroup items when enabling qgroups Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 19/35] btrfs: add a helper to read the tree_root commit root for backref lookup Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 20/35] scsi: core: Don't start concurrent async scan on same host Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 21/35] drm/amdgpu: disable DCN and VCN for navi10 blockchain SKU(v3) Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 22/35] drm/amdgpu: add DID for navi10 blockchain SKU Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 23/35] drm/amd/display: Fixed panic during seamless boot Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 24/35] scsi: ibmvscsi: Fix potential race after loss of transport Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 25/35] drm/amd/display: adding ddc_gpio_vga_reg_list to ddc reg def'ns Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 26/35] vsock: use ns_capable_noaudit() on socket create Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 27/35] nvme-rdma: handle unexpected nvme completion data length Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 28/35] nvmet: fix a NULL pointer dereference when tracing the flush command Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 29/35] staging: mmal-vchiq: Fix memory leak for vchiq_instance Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 30/35] drm/vc4: drv: Add error handding for bind Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 31/35] ACPI: NFIT: Fix comparison to '-ENXIO' Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 32/35] usb: cdns3: gadget: suspicious implicit sign extension Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 33/35] drm/nouveau/nouveau: fix the start/end range for migration Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 34/35] drm/nouveau/gem: fix "refcount_t: underflow; use-after-free" Sasha Levin
2020-11-03 1:18 ` [PATCH AUTOSEL 5.9 35/35] arm64/smp: Move rcu_cpu_starting() earlier Sasha Levin
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