Messages in this thread | | | From | Kyle Moffett <> | Subject | Re: [PATCH] Reduce stack used by lib/hexdump.c | Date | Thu, 6 Dec 2007 00:58:38 -0500 |
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On Dec 05, 2007, at 21:42:35, Joe Perches wrote: > On Wed, 2007-12-05 at 18:18 -0800, Randy Dunlap wrote: >> Joe Perches wrote: >>> Maybe just eliminate the 16 or 32 byte width option and force it >>> to only 16 byte widths. >> Have you checked users (callers)? I'm pretty sure that one of the >> callers wanted 32 and that's why it's there. > > I did. There is only 1 subsystem. That's easy to change. > > drivers/mtd/ubi/debug.c: print_hex_dump(KERN_DEBUG, "", > DUMP_PREFIX_OFFSET, 32, 1, > drivers/mtd/ubi/io.c: print_hex_dump(KERN_DEBUG, "", > DUMP_PREFIX_OFFSET, 32, 1, > > Long lines in the log file are not too easy to read anyway. Using > 16 byte dumps per line instead of 32 isn't painful. > > It gets rid of the allocation, reduces the argument count and makes > the kernel smaller. I think it's all good. > > Every current caller would have to change though.
Alternatively, since print_hex_dump is not a performance-critical path (and usually indicates an error/debug condition), you could probably just make a static "hexdump_lock" spinlock and spin_lock_irqsave()/spin_unlock_irqrestore(). It would always nest inside any other lock (except during crash, where we break locks already for printk()), and I doubt any of the callers would notice the serialization since they're already serialized on the printk buffer.
Cheers, Kyle Moffett
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