baa2f6cedb
Collecting build-ids for long running sessions may take a long time because it needs to traverse the whole just collected perf.data stream of events, marking the DSOs that had hits and then looking for the .note.gnu.build-id ELF section. For things like the 'trace' tool that records and right away consumes the data on systems where its unlikely that the DSOs being monitored will change while 'trace' runs, it is desirable to remove build id collection, so add a -B/--no-buildid option to perf record to allow such use case. Longer term we'll avoid all this if we, at DSO load time, in the kernel, take advantage of this slow code path to collect the build-id and stash it somewhere, so that we can insert it in the PERF_RECORD_MMAP event. Reported-by: Thomas Gleixner <tglx@linutronix.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Zanussi <tzanussi@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
33 lines
808 B
C
33 lines
808 B
C
#ifndef _PERF_LINUX_BITOPS_H_
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#define _PERF_LINUX_BITOPS_H_
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#include <linux/kernel.h>
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#include <asm/hweight.h>
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#define BITS_PER_LONG __WORDSIZE
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#define BITS_PER_BYTE 8
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#define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
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static inline void set_bit(int nr, unsigned long *addr)
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{
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addr[nr / BITS_PER_LONG] |= 1UL << (nr % BITS_PER_LONG);
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}
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static inline void clear_bit(int nr, unsigned long *addr)
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{
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addr[nr / BITS_PER_LONG] &= ~(1UL << (nr % BITS_PER_LONG));
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}
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static __always_inline int test_bit(unsigned int nr, const unsigned long *addr)
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{
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return ((1UL << (nr % BITS_PER_LONG)) &
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(((unsigned long *)addr)[nr / BITS_PER_LONG])) != 0;
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}
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static inline unsigned long hweight_long(unsigned long w)
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{
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return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
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}
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#endif
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