Normally after grabbing the lock it has to be verified we got the right one
to begin with. However, if we are recursing, it must not change thus the
check can be avoided. In particular this avoids a lock read for non-recursing
case which found out the lock was changed.
While here avoid an irq trip of this happens.
Tested by: pho (previous version)
of years since the century, so strip the century out when converting to or
from bcd_clocktime format (the conversion routines will infer century by
pivoting on 70).
The code already pays the cost of reading the lock to obtain the waiters
flag. Checking whether there is more than one reader is not a problem and
avoids dirtying the line.
This also fixes a small corner case: if waiters were to show up between
reading the flag and upgrading the lock, the operation would fail even
though it should not. No correctness change here though.
If there were exactly rowner_retries/asx_retries (by default: 10) transitions
between read and write state and the waiters still did not get the lock, the
next owner -> reader transition would result in the code correctly falling
back to turnstile/sleepq where it would incorrectly think it was waiting
for a writer and decide to leave turnstile/sleepq to loop back. From this
point it would take ts/sq trips until the lock gets released.
The bug sometimes manifested itself in stalls during -j 128 package builds.
Refactor the code to fix the bug, while here remove some of the gratituous
differences between rw and sx locks.
The main routine takes 8 args, 3 of which are almost the same for most uses.
This in particular pushes it above the limit of 6 arguments passable through
registers on amd64 making it impossible to tail call.
This is a prerequisite for further cleanups.
Tested by: pho
the jtag port, so that a tty is not created for it.
This is based on information in the PR and from the vendor website. When
the PR was first opened we had no facility for flagging the jtag ports. I
stumbled across the still-open PR with the idea of closing it, and noticed
that this wee update was needed.
PR: 175893
Before executing a command in a ddb script ddb prints an information
line of the form:
db:1:my-script> command
where 1 is the script's depth level, "my-script" is the scipt's name,
and "command" is the current command in the script.
db_script_exec() uses its 'scriptname' parameter to produce that string.
In the case when db_script_exec() is called from db_run_cmd() the
argument points to db_tok_string that is a global variable used for
command parsing. So, its value changes with every command executed.
This commit changes the code to use the script's name stored in
ds_scriptname to print the line.
MFC after: 2 weeks
instead of pause() in the msleep() function to avoid rounding errors when
converting delay values forth and back. Add a guard for a delay value
of zero milliseconds which is undefined.
MFC after: 1 week
Requested by: Johannes Lundberg <johalun0@gmail.com>
Sponsored by: Mellanox Technologies
It would have been on an actual named pass before, but none were really
appropriate in name. Move it to the recently created SUPPORTDEV pass, which
perfectly describes it and keeps it in the right order.
Getting regulator is good, enabling them is better.
When the mmc stack decide to change the voltage for IO, don't
change the main vcc of the sd/mmc, only the io vcc.
AXP803 and AXP813/818 are very similar, only two regulators differs.
AXP803 is the companion chip for A64/R18
AXP813 is the companion chip for A83T
AXP818 is the companion chip for H8 (~A83T)
Add support for all regulators found in both of them.
Since that change the system call stack traces look like this:
...
sys___sysctl() at sys___sysctl+0x5f/frame 0xfffffe0028e13ac0
amd64_syscall() at amd64_syscall+0x79b/frame 0xfffffe0028e13bf0
fast_syscall_common() at fast_syscall_common+0x101/frame 0xfffffe0028e13bf0
So, db_nextframe() stopped recognizing the system call frame.
This commit should fix that.
Reviewed by: kib
MFC after: 4 days
The reason for this new pass is :
The earlier pass names are really specific (interrupt, timer, scheduler etc ..)
and making a driver that other device driver (that attach at DEFAULT pass)
needs probe at earlier pass can be confiusing. We can live with GPIO driver
at INTERRUPT pass because they are often an interrupt controller too but having
a usb phy driver probed at RESOURCES (or SCHEDULER for example) is silly.
The number was choosen to have a lot of margin if we want to introduce other
pass in the futur.
Reviewed by: ian, imp, kevans
Differential Revision: https://reviews.freebsd.org/D14568
