scsi: make scsi_devinfo infrastructure optional
PATCH 1/1 scsi: make scsi_devinfo infrastructure optional
Add SCSI_QUIRKS config option (default y and dependent on EMBEDDED config option) to allow disabling of scsi_devinfo infrastructure.
The output code size savings are ~14k for CONFIG_SCSI_QUIRKS=n (as measured on x86-32):
CONFIG_SCSI_QUIRKS=y:
text data bss dec hex filename 47342 4368 628 52338 cc72 drivers/scsi/scsi_mod.o 3897 2776 260 6933 1b15 drivers/scsi/scsi_devinfo.o
CONFIG_SCSI_QUIRKS=n:
text data bss dec hex filename 42968 1592 368 44928 af80 drivers/scsi/scsi_mod.o
---
Using CONFIG_SCSI_QUIRKS=n it was possible to shrink the binary code size of the minimal SCSI core configuration by 14% (as measured on x86-32 few kernel versions ago)..
drivers/scsi/Kconfig | 9 +++++++++ drivers/scsi/Makefile | 3 ++- drivers/scsi/scsi_priv.h | 33 +++++++++++++++++++++++++++++++++ 3 files changed, 44 insertions(+), 1 deletion(-)
drivers/scsi/Kconfig +9 -0
@@ -47,6 +47,15 @@ config SCSI_TGT If you want to use SCSI target mode drivers enable this option. If you choose M, the module will be called scsi_tgt. +config SCSI_QUIRKS + bool "SCSI quirks support" if EMBEDDED + default y + help + This option enables support for devices that require settings + that differ from the default. + + If unsure say Y. + config SCSI_NETLINK bool default n
drivers/scsi/Makefile +2 -1
@@ -160,7 +160,8 @@ obj-$(CONFIG_SCSI_WAIT_SCAN) += scsi_wai scsi_mod-y += scsi.o hosts.o scsi_ioctl.o constants.o \ scsicam.o scsi_error.o scsi_lib.o scsi_mod-$(CONFIG_SCSI_DMA) += scsi_lib_dma.o -scsi_mod-y += scsi_scan.o scsi_sysfs.o scsi_devinfo.o +scsi_mod-y += scsi_scan.o scsi_sysfs.o +scsi_mod-$(CONFIG_SCSI_QUIRKS) += scsi_devinfo.o scsi_mod-$(CONFIG_SCSI_NETLINK) += scsi_netlink.o scsi_mod-$(CONFIG_SYSCTL) += scsi_sysctl.o scsi_mod-$(CONFIG_SCSI_PROC_FS) += scsi_proc.o
drivers/scsi/scsi_priv.h +33 -0
@@ -47,6 +47,7 @@ enum { SCSI_DEVINFO_SPI, }; +#ifdef CONFIG_SCSI_QUIRKS extern int scsi_get_device_flags (struct scsi_device *sdev,const unsigned char *vendor,const unsigned char *model);
@@ -61,6 +62,38 @@ extern int scsi_dev_info_remove_list(intextern int __init scsi_init_devinfo (void );extern void scsi_exit_devinfo (void ); +#else +static inline int scsi_get_device_flags (struct scsi_device *sdev, +const unsigned char *vendor, +const unsigned char *model) +{ +return 0 ; +} +static inline int scsi_get_device_flags_keyed (struct scsi_device *sdev, +const unsigned char *vendor, +const unsigned char *model, +int key) +{ +return 0 ; +} +static inline int scsi_dev_info_list_add_keyed (int compatible,char *vendor, +char *model,char *strflags, +int flags,int key) +{ +return 0 ; +} +static inline int scsi_dev_info_add_list (int key,const char *name) +{ +return 0 ; +} +static inline int scsi_dev_info_remove_list (int key) +{ +return 0 ; +} + +static inline int scsi_init_devinfo (void ) {return 0 ; } +static inline void scsi_exit_devinfo (void ) { } +#endif /* scsi_error.c */ extern enum blk_eh_timer_return scsi_times_out (struct request *req);
Quoted 5 lines · Bartlomiej Zolnierkiewicz
Add
SCSI_QUIRKSconfig option (default y and dependent on EMBEDDED config option) to allow disabling ofscsi_devinfoinfrastructure.The output code size savings are ~14k for
CONFIG_SCSI_QUIRKS=n(as measured on x86-32):
I don't understand the point of this patch ... without the quirks SCSI will do the wrong thing on a whole bunch of stuff. The savings look to be tiny ... since the SCSI module is habitually a lot larger than your figures suggest.
James
Quoted 11 lines · James Bottomley
Quoted 5 lines · Bartlomiej Zolnierkiewicz
Add
SCSI_QUIRKSconfig option (default y and dependent on EMBEDDED config option) to allow disabling ofscsi_devinfoinfrastructure.The output code size savings are ~14k for
CONFIG_SCSI_QUIRKS=n(as measured on x86-32):I don't understand the point of this patch ... without the quirks SCSI will do the wrong thing on a whole bunch of stuff. The savings look to be tiny ... since the SCSI module is habitually a lot larger than your figures suggest.
The patch was originally done for embedded ATA-only setups.
Thanks,
Bartlomiej
Quoted 8 lines · Bartlomiej Zolnierkiewicz
Quoted 7 lines · James Bottomley
Quoted 5 lines · Bartlomiej Zolnierkiewicz
Add
SCSI_QUIRKSconfig option (default y and dependent on EMBEDDED config option) to allow disabling ofscsi_devinfoinfrastructure.The output code size savings are ~14k for
CONFIG_SCSI_QUIRKS=n(as measured on x86-32):
Quoted 6 lines
Quoted 4 lines
I don't understand the point of this patch ... without the quirks SCSI will do the wrong thing on a whole bunch of stuff. The savings look to be tiny ... since the SCSI module is habitually a lot larger than your figures suggest.
The patch was originally done for embedded ATA-only setups.
Well, if it's for ATA only then the better course would be extracting libata from scsi. It's also a bit misleading to do sizings on x86, because that doesn't imply embedded to me. Aren't there still ATAPI devices that require the quirks?
Most embedded setups include some form of USB ... again, the pluggable CD/DVD use the quirks table.
Given the potential for disaster even on embedded systems, I don't really think something like this is a good idea.
James
Quoted 14 lines · James Bottomley
Quoted 13 lines · Bartlomiej Zolnierkiewicz
Quoted 11 lines · James Bottomley
Quoted 5 lines · Bartlomiej Zolnierkiewicz
Add
SCSI_QUIRKSconfig option (default y and dependent on EMBEDDED config option) to allow disabling ofscsi_devinfoinfrastructure.The output code size savings are ~14k for
CONFIG_SCSI_QUIRKS=n(as measured on x86-32):I don't understand the point of this patch ... without the quirks SCSI will do the wrong thing on a whole bunch of stuff. The savings look to be tiny ... since the SCSI module is habitually a lot larger than your figures suggest.
Quoted 6 lines
Quoted 1 line
The patch was originally done for embedded ATA-only setups.
Well, if it's for ATA only then the better course would be extracting libata from scsi. It's also a bit misleading to do sizings on x86, because that doesn't imply embedded to me. Aren't there still ATAPI devices that require the quirks?
According to my knowledge all ATAPI quirks are handled locally in libata & sr.
Quoted 2 lines
Most embedded setups include some form of USB ... again, the pluggable CD/DVD use the quirks table.
This was done long time ago specifically for embedded 486-like embedded system w/o USB support and only using flash storage but indeed this is not a common case.
Quoted 2 lines
Given the potential for disaster even on embedded systems, I don't really think something like this is a good idea.
Well, I don't insist on applying it upstream as it is, it is more to show the direction where the possible room for improvements is in case of older/embedded systems and reducing memory/code size usage. [ There were some concerns about it during recent proposal to use more generalized code for support of some rare Intel-like PATA chipsets (which seem to cost ~20k as measured on x86-64 in terms of additional memory/code requirements, though most such systems are x86-32 only so the incurred cost is probably smaller) .]
BTW with some effort we can do on-demand quirk table loading if it ever grows too big in the future.
Thanks,
Bartlomiej
Quoted 16 lines · Bartlomiej Zolnierkiewicz
Quoted 14 lines · James Bottomley
Quoted 13 lines · Bartlomiej Zolnierkiewicz
Quoted 11 lines · James Bottomley
Quoted 5 lines · Bartlomiej Zolnierkiewicz
Add
SCSI_QUIRKSconfig option (default y and dependent on EMBEDDED config option) to allow disabling ofscsi_devinfoinfrastructure.The output code size savings are ~14k for
CONFIG_SCSI_QUIRKS=n(as measured on x86-32):I don't understand the point of this patch ... without the quirks SCSI will do the wrong thing on a whole bunch of stuff. The savings look to be tiny ... since the SCSI module is habitually a lot larger than your figures suggest.
Quoted 8 lines
Quoted 6 lines
Quoted 1 line
The patch was originally done for embedded ATA-only setups.
Well, if it's for ATA only then the better course would be extracting libata from scsi. It's also a bit misleading to do sizings on x86, because that doesn't imply embedded to me. Aren't there still ATAPI devices that require the quirks?
According to my knowledge all ATAPI quirks are handled locally in libata & sr.
Then look again: libata handles the transport quirks and sr handles the capability quirks. SCSI handles the protocol quirks.
Quoted 19 lines
Quoted 2 lines
Most embedded setups include some form of USB ... again, the pluggable CD/DVD use the quirks table.
This was done long time ago specifically for embedded 486-like embedded system w/o USB support and only using flash storage but indeed this is not a common case.
Quoted 2 lines
Given the potential for disaster even on embedded systems, I don't really think something like this is a good idea.
Well, I don't insist on applying it upstream as it is, it is more to show the direction where the possible room for improvements is in case of older/embedded systems and reducing memory/code size usage. [ There were some concerns about it during recent proposal to use more generalized code for support of some rare Intel-like PATA chipsets (which seem to cost ~20k as measured on x86-64 in terms of additional memory/code requirements, though most such systems are x86-32 only so the incurred cost is probably smaller) .]
Quoted 2 lines
BTW with some effort we can do on-demand quirk table loading if it ever grows too big in the future.
But we already have that, if you look. Part of what you're removing is the proc interface that allows on demand loading. If you just want the ability to compile out the built in table and load everything from boot, that's about a two line patch.
James
Quoted 24 lines · James Bottomley
Quoted 23 lines · Bartlomiej Zolnierkiewicz
Quoted 20 lines · James Bottomley
Quoted 8 lines · Bartlomiej Zolnierkiewicz
Quoted 7 lines · James Bottomley
Quoted 5 lines · Bartlomiej Zolnierkiewicz
Add
SCSI_QUIRKSconfig option (default y and dependent on EMBEDDED config option) to allow disabling ofscsi_devinfoinfrastructure.The output code size savings are ~14k for
CONFIG_SCSI_QUIRKS=n(as measured on x86-32):Quoted 6 lines
Quoted 4 lines
I don't understand the point of this patch ... without the quirks SCSI will do the wrong thing on a whole bunch of stuff. The savings look to be tiny ... since the SCSI module is habitually a lot larger than your figures suggest.
The patch was originally done for embedded ATA-only setups.
Well, if it's for ATA only then the better course would be extracting libata from scsi. It's also a bit misleading to do sizings on x86, because that doesn't imply embedded to me. Aren't there still ATAPI devices that require the quirks?
Quoted 4 lines
Quoted 1 line
According to my knowledge all ATAPI quirks are handled locally in libata & sr.
Then look again: libata handles the transport quirks and sr handles the capability quirks. SCSI handles the protocol quirks.
I'm aware of this. What I meant was that I don't know of any real-world ATAPI hardware needing the protocol quirks handling in SCSI.
Quoted 19 lines
Quoted 19 lines
Quoted 2 lines
Most embedded setups include some form of USB ... again, the pluggable CD/DVD use the quirks table.
This was done long time ago specifically for embedded 486-like embedded system w/o USB support and only using flash storage but indeed this is not a common case.
Quoted 2 lines
Given the potential for disaster even on embedded systems, I don't really think something like this is a good idea.
Well, I don't insist on applying it upstream as it is, it is more to show the direction where the possible room for improvements is in case of older/embedded systems and reducing memory/code size usage. [ There were some concerns about it during recent proposal to use more generalized code for support of some rare Intel-like PATA chipsets (which seem to cost ~20k as measured on x86-64 in terms of additional memory/code requirements, though most such systems are x86-32 only so the incurred cost is probably smaller) .]
Quoted 7 lines
Quoted 2 lines
BTW with some effort we can do on-demand quirk table loading if it ever grows too big in the future.
But we already have that, if you look. Part of what you're removing is the proc interface that allows on demand loading. If you just want the ability to compile out the built in table and load everything from boot, that's about a two line patch.
Indeed! Though code savings are smaller using this method..
From: Bartlomiej Zolnierkiewicz <[email protected]>
Subject: [PATCH] scsi: make scsi_devinfo table content optional
Add CONFIG_SCSI_QUIRKS config option (default y and dependent on EMBEDDED config option) to allow disabling of the default scsi_devinfo table content.
The output code size savings are ~7.5k for CONFIG_SCSI_QUIRKS=n (as measured on x86-64):
CONFIG_SCSI_QUIRKS=y:
text data bss dec hex filename 5965 5520 288 11773 2dfd drivers/scsi/scsi_devinfo.o
CONFIG_SCSI_QUIRKS=n:
text data bss dec hex filename 3740 48 288 4076 fec drivers/scsi/scsi_devinfo.o
--- drivers/scsi/Kconfig | 9 +++++++++ drivers/scsi/scsi_devinfo.c | 2 ++ 2 files changed, 11 insertions(+)
drivers/scsi/Kconfig +9 -0
@@ -47,6 +47,15 @@ config SCSI_TGT If you want to use SCSI target mode drivers enable this option. If you choose M, the module will be called scsi_tgt. +config SCSI_QUIRKS + bool "SCSI quirks list" if EMBEDDED + default y + help + This option enables deprecated in-kernel list of devices + that require settings that differ from the default. + + If unsure say Y. + config SCSI_NETLINK bool default n
drivers/scsi/scsi_devinfo.c +2 -0
@@ -53,6 +53,7 @@ static struct {char *revision;/* revision known to be bad, unused */ unsigned flags; } scsi_static_device_list[] __initdata = { +#ifdef CONFIG_SCSI_QUIRKS /* * The following devices are known not to tolerate a lun != 0 scan * for one reason or another. Some will respond to all luns,
@@ -251,6 +252,7 @@ static struct { {"XYRATEX", "RS", "*", BLIST_SPARSELUN | BLIST_LARGELUN}, {"Zzyzx", "RocketStor 500S", NULL, BLIST_SPARSELUN}, {"Zzyzx", "RocketStor 2000", NULL, BLIST_SPARSELUN}, +#endif { NULL, NULL, NULL, 0 }, };
Quoted 6 lines · Bartlomiej Zolnierkiewicz
From: Bartlomiej Zolnierkiewicz <[email protected]>
Subject: [PATCH] scsi: makescsi_devinfotable content optionalAdd
CONFIG_SCSI_QUIRKSconfig option (default y and dependent on EMBEDDED config option) to allow disabling of the defaultscsi_devinfotable content.
Note: all uses of CONFIG_EMBEDDED were recently moved to CONFIG_EXPERT. (see commit 6a108a14fa356ef607be308b68337939e56ea94e)
This one should probably use it too.
Quoted 59 lines
The output code size savings are ~7.5k for
CONFIG_SCSI_QUIRKS=n(as measured on x86-64):
CONFIG_SCSI_QUIRKS=y:text data bss dec hex filename 5965 5520 288 11773 2dfd drivers/scsi/scsi_devinfo.o
CONFIG_SCSI_QUIRKS=n:text data bss dec hex filename 3740 48 288 4076 fec drivers/scsi/scsi_devinfo.oSigned-off-by Bartlomiej Zolnierkiewicz <[email protected]>--- drivers/scsi/Kconfig | 9 +++++++++ drivers/scsi/scsi_devinfo.c | 2 ++ 2 files changed, 11 insertions(+)Index: b/drivers/scsi/Kconfig
===================================================================drivers/scsi/Kconfig +9
-0@@ -47,6 +47,15 @@ config SCSI_TGT If you want to use SCSI target mode drivers enable this option. If you choose M, the module will be called scsi_tgt. +config SCSI_QUIRKS + bool "SCSI quirks list" if EMBEDDED + default y + help + This option enables deprecated in-kernel list of devices + that require settings that differ from the default. + + If unsure say Y. + config SCSI_NETLINK bool default nIndex:
b/drivers/scsi/scsi_devinfo.c
===================================================================drivers/scsi/scsi_devinfo.c +2
-1@@ -53,6 +53,7 @@ static struct {char *revision;/* revision known to be bad, unused */ unsigned flags; } scsi_static_device_list[] __initdata = { +#ifdef CONFIG_SCSI_QUIRKS /* * The following devices are known not to tolerate a lun != 0 scan * for one reason or another. Some will respond to all luns, @@ -251,6 +252,7 @@ static struct { {"XYRATEX", "RS", "*", BLIST_SPARSELUN | BLIST_LARGELUN}, {"Zzyzx", "RocketStor 500S", NULL, BLIST_SPARSELUN}, {"Zzyzx", "RocketStor 2000", NULL, BLIST_SPARSELUN}, +#endif { NULL, NULL, NULL, 0 }, }; --