[PATCH 3.13.y-ckt 58/78] mmc: remove bondage between REQ_META and reliable write

From	Kamal Mostafa <kamal@canonical.com>
Newsgroups	linux.kernel
Subject	[PATCH 3.13.y-ckt 58/78] mmc: remove bondage between REQ_META and reliable write
Date	2015-12-17 02:00 +0100
Message-ID	<qGv5g-DM-5@gated-at.bofh.it> (permalink)
References	<qGuVA-Ae-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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3.13.11-ckt32 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Luca Porzio <lporzio@micron.com>

commit d3df0465db00cf4ed9f90d0bfc3b827d32b9c796 upstream.

Anytime a write operation is performed with Reliable Write flag enabled,
the eMMC device is enforced to bypass the cache and do a write to the
underling NVM device by Jedec specification; this causes a performance
penalty since write operations can't be optimized by the device cache.

In our tests, we replayed a typical mobile daily trace pattern and found
~9% overall time reduction in trace replay by using this patch. Also the
write ops within 4KB~64KB chunk size range get a 40~60% performance
improvement by using the patch (as this range of write chunks are the ones
affected by REQ_META).

This patch has been discussed in the Mobile & Embedded Linux Storage Forum
and it's the results of feedbacks from many people. We also checked with
fsdevl and f2fs mailing list developers that this change in the usage of
REQ_META is not affecting FS behavior and we got positive feedbacks.
Reporting here the feedbacks:
http://comments.gmane.org/gmane.linux.file-systems/97219
http://thread.gmane.org/gmane.linux.file-systems.f2fs/3178/focus=3183

Signed-off-by: Bruce Ford <bford@micron.com>
Signed-off-by: Luca Porzio <lporzio@micron.com>
Fixes: ce39f9d17c14 ("mmc: support packed write command for eMMC4.5 devices")
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
 drivers/mmc/card/block.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index a6bf69b..76671d6 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -62,8 +62,7 @@ MODULE_ALIAS("mmc:block");
 #define MMC_SANITIZE_REQ_TIMEOUT 240000
 #define MMC_EXTRACT_INDEX_FROM_ARG(x) ((x & 0x00FF0000) >> 16)
 
-#define mmc_req_rel_wr(req)	(((req->cmd_flags & REQ_FUA) || \
-				  (req->cmd_flags & REQ_META)) && \
+#define mmc_req_rel_wr(req)	((req->cmd_flags & REQ_FUA) && \
 				  (rq_data_dir(req) == WRITE))
 #define PACKED_CMD_VER	0x01
 #define PACKED_CMD_WR	0x02
@@ -1328,13 +1327,9 @@ static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq,
 
 	/*
 	 * Reliable writes are used to implement Forced Unit Access and
-	 * REQ_META accesses, and are supported only on MMCs.
-	 *
-	 * XXX: this really needs a good explanation of why REQ_META
-	 * is treated special.
+	 * are supported only on MMCs.
 	 */
-	bool do_rel_wr = ((req->cmd_flags & REQ_FUA) ||
-			  (req->cmd_flags & REQ_META)) &&
+	bool do_rel_wr = (req->cmd_flags & REQ_FUA) &&
 		(rq_data_dir(req) == WRITE) &&
 		(md->flags & MMC_BLK_REL_WR);
 
-- 
1.9.1

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Thread

[3.13.y-ckt stable] Linux 3.13.11-ckt32 stable review Kamal Mostafa <kamal@canonical.com> - 2015-12-17 01:50 +0100
  [PATCH 3.13.y-ckt 38/78] vfs: Make sendfile(2) killable even better Kamal Mostafa <kamal@canonical.com> - 2015-12-17 01:50 +0100
  [PATCH 3.13.y-ckt 56/78] sched/core: Clear the root_domain cpumasks in init_rootdomain() Kamal Mostafa <kamal@canonical.com> - 2015-12-17 01:50 +0100
  [PATCH 3.13.y-ckt 72/78] packet: only allow extra vlan len on ethernet devices Kamal Mostafa <kamal@canonical.com> - 2015-12-17 01:50 +0100
  [PATCH 3.13.y-ckt 62/78] tcp: md5: fix lockdep annotation Kamal Mostafa <kamal@canonical.com> - 2015-12-17 01:50 +0100
  [PATCH 3.13.y-ckt 63/78] ARM: dts: Kirkwood: Fix QNAP TS219 power-off Kamal Mostafa <kamal@canonical.com> - 2015-12-17 01:50 +0100
  [PATCH 3.13.y-ckt 47/78] drm/radeon: make some dpm errors debug only Kamal Mostafa <kamal@canonical.com> - 2015-12-17 01:50 +0100
  [PATCH 3.13.y-ckt 04/78] iio: lpc32xx_adc: fix warnings caused by enabling unprepared clock Kamal Mostafa <kamal@canonical.com> - 2015-12-17 01:50 +0100
  [PATCH 3.13.y-ckt 27/78] USB: option: add XS Stick W100-2 from 4G Systems Kamal Mostafa <kamal@canonical.com> - 2015-12-17 01:50 +0100
  [PATCH 3.13.y-ckt 68/78] net: mvneta: fix bit assignment for RX packet irq enable Kamal Mostafa <kamal@canonical.com> - 2015-12-17 01:50 +0100
  [PATCH 3.13.y-ckt 75/78] net: ip6mr: fix static mfc/dev leaks on table destruction Kamal Mostafa <kamal@canonical.com> - 2015-12-17 01:50 +0100
  [PATCH 3.13.y-ckt 08/78] x86/fpu: Fix 32-bit signal frame handling Kamal Mostafa <kamal@canonical.com> - 2015-12-17 01:50 +0100
  [PATCH 3.13.y-ckt 64/78] isdn: Partially revert debug format string usage clean up Kamal Mostafa <kamal@canonical.com> - 2015-12-17 01:50 +0100
  [PATCH 3.13.y-ckt 65/78] remoteproc: avoid stack overflow in debugfs file Kamal Mostafa <kamal@canonical.com> - 2015-12-17 01:50 +0100
  [PATCH 3.13.y-ckt 76/78] unix: avoid use-after-free in ep_remove_wait_queue Kamal Mostafa <kamal@canonical.com> - 2015-12-17 01:50 +0100
  [PATCH 3.13.y-ckt 35/78] powerpc/tm: Block signal return setting invalid MSR state Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:00 +0100
  [PATCH 3.13.y-ckt 58/78] mmc: remove bondage between REQ_META and reliable write Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:00 +0100
  [PATCH 3.13.y-ckt 55/78] wan/x25: Fix use-after-free in x25_asy_open_tty() Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:00 +0100
  [PATCH 3.13.y-ckt 45/78] RDS: fix race condition when sending a message on unbound socket Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:00 +0100
  [PATCH 3.13.y-ckt 46/78] btrfs: fix signed overflows in btrfs_sync_file Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:00 +0100
  [PATCH 3.13.y-ckt 37/78] fix sysvfs symlinks Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:00 +0100
  [PATCH 3.13.y-ckt 51/78] target: Fix race for SCF_COMPARE_AND_WRITE_POST checking Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:00 +0100
  [PATCH 3.13.y-ckt 48/78] nfs: if we have no valid attrs, then don't declare the attribute cache valid Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:00 +0100
  [PATCH 3.13.y-ckt 49/78] xen/gntdev: Grant maps should not be subject to NUMA balancing Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:00 +0100
  [PATCH 3.13.y-ckt 54/78] Fix a memory leak in scsi_host_dev_release() Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:00 +0100
  [PATCH 3.13.y-ckt 57/78] x86/signal: Fix restart_syscall number for x32 tasks Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:00 +0100
  [PATCH 3.13.y-ckt 43/78] arm64: KVM: Fix AArch32 to AArch64 register mapping Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:00 +0100
  [PATCH 3.13.y-ckt 50/78] iscsi-target: Fix rx_login_comp hang after login failure Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:00 +0100
  [PATCH 3.13.y-ckt 60/78] usb: musb: core: fix order of arguments to ulpi write callback Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:00 +0100
  [PATCH 3.13.y-ckt 53/78] block: Always check queue limits for cloned requests Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:00 +0100
  [PATCH 3.13.y-ckt 03/78] stackprotector: Introduce CONFIG_CC_STACKPROTECTOR_STRONG Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:00 +0100
  [PATCH 3.13.y-ckt 59/78] sctp: translate host order to network order when setting a hmacid Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:00 +0100
  [PATCH 3.13.y-ckt 52/78] target: fix COMPARE_AND_WRITE non zero SGL offset data corruption Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:00 +0100
  [PATCH 3.13.y-ckt 36/78] ARC: dw2 unwind: Remove falllback linear search thru FDE entries Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:10 +0100
  [PATCH 3.13.y-ckt 31/78] fat: fix fake_offset handling on error path Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:10 +0100
  [PATCH 3.13.y-ckt 42/78] ring-buffer: Update read stamp with first real commit on page Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:10 +0100
  [PATCH 3.13.y-ckt 15/78] mac80211: mesh: fix call_rcu() usage Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:10 +0100
  [PATCH 3.13.y-ckt 44/78] drm/radeon: make rv770_set_sw_state failures non-fatal Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:10 +0100
  [PATCH 3.13.y-ckt 30/78] ALSA: hda - Apply HP headphone fixups more generically Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:10 +0100
  [PATCH 3.13.y-ckt 33/78] parisc: Drop unused MADV_xxxK_PAGES flags from asm/mman.h Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:10 +0100
  [PATCH 3.13.y-ckt 19/78] MIPS: KVM: Fix ASID restoration logic Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:10 +0100
  [PATCH 3.13.y-ckt 23/78] xhci: Fix a race in usb2 LPM resume, blocking U3 for usb2 devices Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:10 +0100
  [PATCH 3.13.y-ckt 32/78] kernel/signal.c: unexport sigsuspend() Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:10 +0100
  [PATCH 3.13.y-ckt 21/78] MIPS: KVM: Uninit VCPU in vcpu_create error path Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:10 +0100
  [PATCH 3.13.y-ckt 12/78] USB: serial: option: add support for Novatel MiFi USB620L Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:10 +0100
  [PATCH 3.13.y-ckt 22/78] xhci: Workaround to get Intel xHCI reset working more reliably Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:10 +0100
  [PATCH 3.13.y-ckt 16/78] usb: dwc3: gadget: let us set lower max_speed Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:10 +0100
  [PATCH 3.13.y-ckt 40/78] nfs4: start callback_ident at idr 1 Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:10 +0100
  [PATCH 3.13.y-ckt 14/78] ASoC: wm8962: correct addresses for HPF_C_0/1 Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:10 +0100
  [PATCH 3.13.y-ckt 41/78] ALSA: hda - Fix headphone noise after Dell XPS 13 resume back from S3 Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:10 +0100
  [PATCH 3.13.y-ckt 13/78] USB: ti_usb_3410_5052: Add Honeywell HGI80 ID Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:10 +0100
  [PATCH 3.13.y-ckt 28/78] usblp: do not set TASK_INTERRUPTIBLE before lock Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:10 +0100
  [PATCH 3.13.y-ckt 20/78] MIPS: KVM: Fix CACHE immediate offset sign extension Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:10 +0100
  [PATCH 3.13.y-ckt 39/78] vfs: Avoid softlockups with sendfile(2) Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:10 +0100
  [PATCH 3.13.y-ckt 25/78] ALSA: hda - Add fixup for Acer Aspire One Cloudbook 14 Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:10 +0100
  [PATCH 3.13.y-ckt 29/78] mac: validate mac_partition is within sector Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:10 +0100
  [PATCH 3.13.y-ckt 24/78] x86/cpu: Fix SMAP check in PVOPS environments Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:10 +0100
  [PATCH 3.13.y-ckt 26/78] arm64: restore bogomips information in /proc/cpuinfo Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:10 +0100
  [PATCH 3.13.y-ckt 05/78] iio:ad5064: Make sure ad5064_i2c_write() returns 0 on success Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:20 +0100
  [PATCH 3.13.y-ckt 10/78] ALSA: usb-audio: prevent CH345 multiport output SysEx corruption Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:20 +0100
  [PATCH 3.13.y-ckt 11/78] ALSA: usb-audio: work around CH345 input SysEx corruption Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:20 +0100
  [PATCH 3.13.y-ckt 07/78] iio:ad7793: Fix ad7785 product ID Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:20 +0100
  [PATCH 3.13.y-ckt 01/78] tty: fix stall caused by missing memory barrier in drivers/tty/n_tty.c Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:20 +0100
  [PATCH 3.13.y-ckt 09/78] ALSA: usb-audio: add packet size quirk for the Medeli DD305 Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:20 +0100
  [PATCH 3.13.y-ckt 06/78] iio: ad5064: Fix ad5629/ad5669 shift Kamal Mostafa <kamal@canonical.com> - 2015-12-17 02:20 +0100

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